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Photpgraphic 

Sciences 
Corporation 


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23  WEST  MAIN  STREET 

WEBSTER,  NY.  14530 

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<v 


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CiHM/ICMH 

Microfiche 

Series. 


CIHM/ICMH 
Collection  de 
microfiches. 


Canadian  Institute  for  Historical  Mlcroreproductions  /  Institut  canadien  de  m'croreproductions  historiques 


<m 


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Technical  and  Bibliographic  Notes/Notes  techniques  et  bibliographiques 


The  Institute  has  attempted  to  obtain  the  best 
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copy  which  may  be  bibliographically  unique, 
which  may  alter  any  of  the  images  in  the 
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L'Institut  a  microfilm^  le  meilleur  exemplaire 
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de  cet  exemplaire  qui  sont  peut-dtre  uniques  du 
point  de  vue  bibliographique,  qui  peuvent  modifier 
une  image  reproduite,  ou  qui  pepjvent  exiger  une 
modification  dans  la  m^thode  normale  dc  filmage 
sont  indiquds  ci-dessous. 


n 


n 


n 


Coloured  covers/ 
Ccuverture  de  cculeur 


I      I    Covers  damaged/ 


Couverture  endommag^e 


Covers  restored  and/or  laminated/ 
Couverture  restaur^e  et/ou  pellicul^e 


Cover  title  missing/ 

Le  titre  de  couverture  manque 


□    Coloured  maps/ 
Cartes  g^ographiques  en  couleur 


Coloured  ink  (i.e.  other  than  blue  or  black)/ 
ere  de  couleur  (i.e.  autre  que  bleue  ou  noire) 


I      I    Coloured  plates  and/or  illustrations/ 


Planches  et/ou  illustrations  en  couleur 

Bound  with  other  material/ 
Reli^  avec  d'autres  documents 


D 


V 


D 
0 


D 


Coloured  pages/ 
Piges  de  couleur 

Pages  damaged/ 
Pages  endommagdes 

Pages  restored  and/or  laminated/ 
Pages  restaurdes  et/ou  pellicul^es 

Pages  discoloured,  stained  or  foxed/ 
Pages  J6color6es,  tachet6es  ou  piqu^es 

Pages  detached/ 
Pages  ddtach^es 

Showthrough/ 
Transparence 


I      I    Quality  of  print  varies/ 


Quality  in^gale  de  I'impression 

Includes  supplementary  material/ 
Comprend  du  materiel  supplementaire 


0 


n 


Tight  binding  may  cause  shadows  or  distortion 
along  interior  margin/ 

La  reliure  serree  peut  causer  de  I'ombre  ou  de  la 
distortion  le  long  de  la  marge  intdrieure 

Blank  leaves  added  during  restoration  may 
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have  been  omiited  from  filming/ 
II  se  peut  que  rertaines  pages  blanches  ajout^es 
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mais,  lorsque  cela  dtait  possible,  ces  pages  n'ont 
pas  6t6  i\\m6es. 


D 
D 


Only  edition  availabSe/ 
Seule  Edition  disponible 

Pages  wholly  or  partially  obscured  by  errata 
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obtenir  la  meilleure  image  possible. 


D 


Additional  comments:/ 
Commentaires  suppl^mentaires: 


This  item  is  filmed  at  the  reduction  ratio  checked  below/ 

Ce  document  est  filmd  au  taux  de  reduction  indiqu6  ci-dessous. 


10X 

14X 

18X 

22X 

26X 

3CX 

y 

1?.X 


16X 


2QX 


24X 


28X 


32X 


The  copy  filmed  here  has  been  reproduced  thanks 
to  the  generosity  of: 

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The  images  appearing  here  are  the  best  quality 
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L'exemplaire  fllmd  fut  reproduit  grSce  d  la 
96n6rosit6  de: 

Bibliothdque 

Affairen  indiennes  et  du  Nord 

Les  images  suivantes  ont  dt6  reproduites  avec  le 
plus  grand  soin,  cornpte  tenu  de  la  condition  et 
de  la  nettet6  de  l'exemplaire  filmd,  et  en 
conformity  avec  les  conditions  du  contrat  de 
filmage. 


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sion, or  the  back  cover  when  appropriate.  All 
other  original  copies  are  filmed  beginning  on  the 
first  page  with  a  printed  or  illustrated  impres- 
sion, and  ending  en  the  last  page  with  a  printed 
or  illustrated  impression. 


Les  exemplaires  originaux  dont  la  couverture  en 
papier  est  imprimde  son*  filmis  en  commenpant 
par  le  premier  plat  et  en  iarminant  soit  par  la 
dernidre  page  qui  comporte  une  empreinte 
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d'impression  ou  d'illustration  et  en  terminant  par 
la  dernidre  page  qui  comporte  une  telle 
empreinte. 


The  last  lecorded  frame  on  each  microfiche 
shall  contain  the  symbol  —^'  (meaning  "CON- 
TINUED "),  or  the  symbol  V  (meaning  'END"), 
whichever  applies. 


Un  des  symboles  suivants  apparaitra  sur  la 
dernidre  image  de  cheque  microfiche,  selon  le 
cas:  le  symbole  — ►  signifie  "A  SUIVRE",  le 
symbole  V  signifie  "FIN". 


Maps,  plates,  charts,  etc.,  may  be  filmed  at 
different  reduction  rdtios.  Those  too  large  to  be 
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beginning  in  the  upper  left  hand  corner,  left  to 
right  and  top  to  bottom,  as  many  frames  as 
required.  The  following  diagrams  illustrate  the 
method: 


Les  cartes,  planches,  tableaux,  etc.,  peuvent  dtre 
film6s  d  des  taux  do  reduction  diffdrents. 
Lorsque  le  document  est  trop  grand  pour  dtre 
rerroduit  en  un  seul  clichd,  il  est  filmd  d  partir 
de  Tangle  supdrieur  gauche,  de  gauche  d  droite, 
et  de  haut  en  bas,  en  prenant  le  nombre 
d'images  ndcessaire.  Les  diagrammes  suivants 
illustrent  la  mdthode. 


1 

2 

3 

1 

2 

3 

4 

5 

6 

'//^ 


^ 


LAKES 


OF 


NOETH    AMEEICA 


A  READING  LESSON 
FOR  STUDENTS  OF  GEOGRAPHY  AND  GEOLOGY 


BY 


ISRAEL  C.  RUSSELL 

TBOFESSOR  OF  GEOLOGY,  U.NIVF.K8ITV   OF  MICU1GA17 


GLXN  &  COMPANY 

BOSTON  •  XKW  YORK      CHICAGO  •  I.ONDOX 


SB 


Ciil'VliKiiiT,  1895. 

liV 

ISKAKL  C.  Ul'SSKLL 


ALL  BiaUTS  llliSKUVED 
30.7 


iCht  flttitn.-tiim   Drtsx 

(,1  \N    \    1   i)M  r  \  \  Y  ■  I'l-'i- 


Ann  Arbor,  Michwan, 
April  12,  IH'M. 


GROVE    KARL    GILBF.RT, 

V.    S.    OKOLOOICAL    SIRVKT, 
WA91IIX(JT0N,  D.  C. 


My  Dear  Sir  :  — 

It  is  now  fourtee,,  years  since  you  first  «„i.,ed  „.y  f„ofsteps  to  the  beaches  of  Lake  »onne- 
vill  an.,  po.nte.  out  .he  striking  contrasts  i„  the  sc.pturin,  of  the  n.ountains  above  and  beh.w 
the  hor.on  to  wh.ch  that  ancient  sea  fiooac  the  now  desert  valleys  of  Utah.     For  several  years 

Mnula    lake.  „.  Nevada,  California,  Oregon,  and   Washington;   and  through  your  a.lvice  and 
su«,es^.,.s  1  was  enabled  to  see  nuu.y  .hin.s  ,hat  otherwise  n.inht  have  escaped  notice 

™«  yitin.  t:.,s  little  book,  which  so  inadeauately  describes  son.e  of  the  n.ost  interesting 

acknou  ledge  o    your  volume  on  Lake  Bonneville  and  of  your  more  general  discussion  of  the 
lopography  of  Lake  Shores-books  that  are  numbered  an.ong  the  classics  of  An.erican  geolo-'y 

.edica";-::;:^:;::^""^'"^" "  ^'^  ~"'^'"  '"^•^"^^"--  ^  ^^«  -  ^^  ='""-'  - 

I  remain,  very  respectfully, 


ISRAEL  C.  RUSSELL. 


PREFATOPvY    I^TOTE. 


A  lau(;h  ijortiou  of  the  facts  [)eitiiiiiiiig-  to  the  lakes  of  North  America, 
jjieseuted  in  this  hook,  were  gleaned  hy  the  writer  during  thirteen  years' 
geological  work  for  the  National  (iovernnient,  and  are  lecorded  principal- 
ly in  the  jnihlications  of  the  U.  S.  Geological  Survey.  The  facilities  for 
exploration  afforded  hy  my  connect' '»n  with  (iovernnient  surveys  enahled 
nie  to  visit  yarious  parts  of  the  United  States,  inclusive  of  Alaska,  and  to 
ohserve  many  phases  in  the  topographical  development  of  our  continent. 

The  puhlications  of  the  U.  S.  (Jeological  Survey,  and  of  several  State 
surveys,  also  contain  the  records  of  ohservations  by  others,  relating  to 
the  subject  here  treated,  which  have  been  freely  used.  It  is  hoped  that 
this  popular  presentation  of  a  small  part  of  the  lesults  cf  the  various 
surveys  referred  to  Avill  serve  to  direct  attention  to  tlie  rich  and  varied 
store  of  information  contained  in  the  reports  of  my  colleagues  and  fellow- 
workers. 

Besides  the  publications  of  official  surveys,  many  pajjere  relating  to 
the  subject  here  discussed  have  appeared  in  journals,  proceedings  of 
scientific  societies,  etc.,  to  which  references  may  be  found  in  footnotes  in 
this  volume. 

The  origin  of  lake  basins  and  the  history  of  the  great  cycles  in  the 
development  of  the  relief  of  the  land  to  which  they  pertain,  have  Ijeen 
discussed  especially  by  Professor  W.  M.  Davis,  of  Harvard  University. 
Professor  Davis  lias  also  read  the  manuscript  of  this  Iwok  and  kindly 
given  me  the  benefit  of  his  criticisms  and  suggestions. 

I.  C.  II. 


INTRODUCTlOiq". 


Lakes  have  their  Inrth  iind  ileath  in  the  t<)pc)jTriV[)hic  development  of 
the  liiiid.  A  certain  chiss  form  a  eharacteristie  feature  of  hinds  recently 
elevated  above  the  sea;  othew  belong  with  the  earlier  stages  (ir  youtii  of 
streams;  while  still  others  iippear  during  matuiity  or  in  the  old  age 
of  the  rivers  to  which  they  owe  their  origin.  I^akes  of  a  different  ty[)e 
are  associated  with  modifications  of  topography  due  to  glaciid  and  (o 
volcanic  agencies,  and  to  movements  of  elevation  and  depression  in  tlie 
eai'th's  crust. 

Lakes,  like  mountains  and  rivers,  have  life  histories  which  exhibit 
varying  stages  from  youth  through  maturity  to  old  age.  The  span  of 
their  existence  varies  as  do  the  lives  of  animals  and  jdants.  In  :irid 
regions  they  are  frequently  born  of  a  single  shower  and  disappear  as 
quickly  when  the  skies  are  again  briglit;  their  brief  existence  may  be 
said  to  resemble  the  lives  of  the  Ephemera.  Again,  the  conditions  are 
such  that  lakes  perhaps  hundreds  of  square  miles  in  area,  are  formed  each 
winter  and  evaporate  to  dryness  during  the  succeeding  summer;  these 
may  be  compared  with  the  annual  plants,  so  regular  are  their  periods. 
Still  othera  exist  for  a  term  of  yeara  and  only  disappear  during  seasons  of 
exceptional  aridity ;  but  the  greater  num])er  of  iidand  water  bodies 
resemble  the  Sequoia,  and  endure  for  centuries  with  but  little  apparent 
change.  So  long  are  the  lives  of  many  individuals  that  human  history 
has  recorded  only  slight  changes  in  their  outlines,  but  to  the  geologist 
even  these  are  seen  to  be  of  recent  origin  and  the  day  of  their  extinction 
not  remote. 

The  tracing  of  the  life  histories  of  lakes  and  the  recognition  of  the 
numerous  agencies  that  vary  their  lives  and  lead  to  their  death,  gives  to 
this  branch  of  physiography  one  of  its  principal  charms. 


^mtm 


vUi 


iNTit<)i)i(rrioN. 


Mi- 


Lakes  are  also  expiessive  of  cliinatlc  coiulitions.  In  hnniid  n'^ions 
they  usually  overflow,  are  fresii,  and  vary  hut  HJij^'htly  in  ;in'a  or  in  (It'itth, 
from  season  to  season,  and  from  i-entury  lo  ctMitury.  In  arid  lands  tlu-y 
are  frequently  without  outlets  and  eonst'tjuently  alkaliiu!  and  saline,  and 
fluctuate  in  sympathy  with  even  the  nunor  chant^'es  in  their  climntie 
environment. 

The  history  of  a  lake  l)e][,nns  with  the  oricfin  of  its  hasin  and  considers 
amon^'  other  suhjects  the  movenu'uts  of  its  waters,  the  changes  it  pro- 
duees  in  the  topo^naphy  of  its  shores,  its  relations  to  climate,  its 
geoloKicid  functions,  its  connection  with  [dant  and  animal  life,  etc.  It  is 
in  this  general  order  that  the  lakes  of  Ncnth  America  are  considered  in 
the  present  volume.  The  standpoint  from  which  the  suhject  is  treated  is 
that  of  the  geologist  and  geographer,  its  relation  to  man  being  left  to  the 
archaeologist  and  the  historian. 


C  ()  N  T  E  ]S^  T  S. 


INri{01)L<  TION. 

ril.VI'TKIt    I. 

ORIGIN    OF   LAKE    BASINS, 
l)i:i'iiKNsiOKs   ON   Ni;w    L.\m>    Aiii,a«*    .  ... 

JJamin-*  nil:   ro  Atmosi-iikiiic  A(ikn<  ii;h       ,         ,         ,         , 
"  '•      ■•   Ai^iKors  A<ii:X(  ii;s  ,         .         ... 

"  "      "  (ii.A(  lAi,  A(;i:xciK«       .         ,         ,         , 

"  "      "  Volcanic  A(iKNcii;H        .        ,        , 

"  "        "    ImI'ACT   ()!■    MiCTKOKS     .  .  ,  , 

"  "        "    KAIITIigiAKKH 

"  "      "  <)ii<;anic    AciKNciKs 

*'  "        "    MoVEMKNTS    IN    Tin;    KaIITII's    CiU  ST 

"          "      "  Land-slides         .         ,         .         .        .        . 
"          "      '•  CiiEMicAi,  Action  .         .        ...         « 
C'ONCLrSION 


I'AdK 

.       1 
8 

.     r, 

10 

r 

.      17 
24 


■J(i 
28 
.•11 

;ji 
:i'i 


ClIAI'TEK     II. 

MOVEMENTS    OF   LAKE   WATERS   AND   THE    GEOLOGICAL    FUNCTIONS 

OF    LAKES. 

Tides ...j 

Waves  and  Cuhhents oo 

**'^""'^ ;5n 

Temi-ekatlre .),-, 

Infi,i:ence  OP  Lakes  on  Climate .         .     .']7 

Influence  of  Lakes  on  the  Flow  of  Streams       .         ...         .  .         .         ;J8 

Lakes  as  Settling  Basins     ....  qo 

•  •  •  •  •  •  •  •  •  .  .01/ 

Mechanical  Sediments 4j 

Chapter  IIL 

TOPOGRAPHY  OF  LAKE  SHORES. 

Sea  Cliffs ^o 

Terraces ,45 


m 


CONTENTS. 


Embankments  . 
1)klta« 
IcE-nuiLT  Walls 


PAOE 

.     4(t 

48 

.     51 


Chapter  IV. 
RELATION   OF   LAKES   TO   CLIMATIC   CONDITIONS. 

Fresh  Ldhcu. 


Chemical  Composition 

Types  of  Fkesh  Lakes  

The    LAt;uENTiAN    Lakes 

The  U.   S.  Lake  Sihvev 

ClIEMiSTUY    OK    THE    WaTEHS    ')K    THE    St.     LaWUEM  E 

EuosioN  OK  Lake  Shokes 

CoMSIERCE    and    FiSIIEKIES 


Mountain  Lakes. 


Lake  Tahoe    , 
Lake  Cii:;LAN 


SiiUne  Lakes. 


Saline  Lakes  ok  Oceanic  Oh:  in 
Saline  Lakes  of  Tkrhestrial  Orujin 
Chemical  Precipitates 
Great  Salt  Lake        .... 
Mono  Lake      ..... 


oil 

67 
57 
57 
50 
(!() 
(il 


03 
05 


(i!) 
70 
71 

77 

8a 


ii;i 


ClIAP'.ER    V. 

THE  LIFE   HISTORIES   OP   LAKES. 

Lakep  of  Himii)  Regions 

Lakes  of  Arid  Regions 


DO 
03 


Chapter  VL 
STUDIES   OF   SPECIAL   LACUSTRAL   HISTORIES. 

Pleistocene  Lakes  of  the  Lairentian  Basin 

Lake  Agassi/ •         .         . 

Pleistocene  Lakes  of  the  Great  Basin • 

Lakes  of  the  Remote  Past 

Index     


00 
103 
100 
114 
1-22 


PAOE 

.     4(t 

48 

.     51 


ILLUSTPATIOJ^-S. 


01 

57 
57 
5!) 
(iO 
(il 


(i5 


C.O 
70 
71 

77 
83 


90 
03 


1()() 

114 

122 


PlATF       1 

a 

2. 

(1 

3. 

a 

4. 

a 

5. 

u 

«. 

a 

7. 

ii 

8. 

u 

0. 

(( 

10. 

ti 

11. 

tb 

12. 

(4 

13. 

tl 

14. 

(( 

15. 

(i 

16. 

(( 

17. 

fc( 

18. 

*' 

19. 

t( 

20. 

u 

21. 

(fc 

22. 

i( 

23. 

FlC.lRE    1. 

t( 

2. 

l( 

3. 

;i 

4 

(4 

6. 

li 

6. 

ti 

7. 

t( 

8. 

(t 

9. 

()x-no\v  Lakes,  Loweu  ^Iissihrippi  , 

Vie-      jf  !Stocktos  Bar,  Utah   .         .         ,  ■       .         ,         .         , 

Mat    >f  STocKTf)X  Bar,  Utah , 

Mai-  of  Gravfi,  Bar  retainin<;  HiMDoi.irr  Lake,  Nevmia     . 

Mai"  of  Crater  Lake,  ORE<;oy       •■...... 

Sketch  of  Ahert  Lake,  Oregon- . 

Chart  of  Lairentian-  La.ve*,  snowisr;  rREVAii.iNr,  Cirrents 
Se.\-ci..ff      in      BoiLiJEK     Ceav,      South      Maxitou      Island,      Lake 
Michigan    .         *        .         .        .        .        .        .        . 

Sea-ci.iff  IV  San-iiston'E,  Ar  Train  Island,  Lake  Sii-erior  . 
E.mhankment  formed  in  Lake  Bonneville,  Wellsville,  Utah 
Gravel  Spit,  Shore  of  Ar  Train    Island,    Lake    Siperior 
A  Kecitrved  SuT,  Gkaxd  Traverse  Bay,  MiciiitiAN     .         .         .         . 

Sea-CLII  FH    AND    TeRRACES    FORMED    ON    THE    SllORE    OF   LaKE    BoNNEVILLE 

OyL'iRRH  Range,   Utah 

Map  OF  Saline  and  Alkaline  Lakes  in  the  Arid  Region    . 
Map  OF  Great  Salt  Lake,  Utah,   showing;  Changes  in  Area    . 
The  Hi':  I  Sierra,  from  North  Shore  of  Mono  Lake,   California 

Map  of  Mo.vo  Lake,   California 

Map  of  Lake  Iroqlois 

Map  of  Lakes  Bonneville  and  Lahovtan    .         .         .         .         .         , 
TiFA  Towers  on  tsie  Shore  of  Pvhamid  Lake,   Nevada 

TiFA    f;KAGS,    SHOWING    Si  CCESSIVE    DEPOSITS,    CaRSON    DesERT,   NeVADA 

Typical  Specimen  of  Thinolitic  Tcfa 

Pyramid  Island,  Pyramid  Lake,  Nevada     .         .         , 

Cross    Secttovs    of    the    CaSons    of    Canadian    and    Mora    Rivers, 

New   Mexico 

Profile   of  a   Sea-clifp  and  Terrace 

Profile   of  a  Cct-and-Built  Terrace  .         ,        , 

Sketch  Map  op  an  Emrankment 

Map    of    Sand    Bar    ahoit    the    Head  of   Lake   Scperior 
Map   of   Sand   Bar   on   the   Soith    Shore   of  Lake    Ontario 

Section   of   a   Delta 

Diagram    showing    the    Rise    and   Fall   of   Lake   Laiiontan 
Diagram  showing  the  Relation  of  the  Terraces  of  Lake  Lahontan 

TO  Pyramid  Lake  


Page 

•       8 

.      10 

12 

.      14 

20 

,     20 

;!4 

42 
,     44 

40 

,     48 
50 

52 

70 

78 

84 

8h 

08 

10!! 

110 

112 

no 

120 

18 
44 

47 

48 
49 
60 

108 

111 


LAKES   OF  NORTH  AMERICA. 


CHAPTER   I. 


ORIGIN    OP    LAKE    BASINS. 


Difficulties  arise  in  cla.ssifyino-  lake  basins,  similar  in  character  to 
those  met  with  when  a  systematic  discussion  of  cfhiciers,  rivers,  mountains 
and  other  features  of  the  earth's  surface  is  attempted.  That  is,  there  are 
no  natural  fi^ron[)s  se[)arated  by  hard  and  fast  linos,  into  which  they 
naturally  fall.  Certain  types  may  be  selected,  however,  answerint,''  to 
genera  among  })lauts  and  animals,  about  which  most  lakes  may  he 
g;oui)ed.  In  selecting  these  types  we  are  guided  by  their  mode  of  origin, 
and  are  thus  led  to  an  incomi)lete  genetic  classification,  based  on  the 
natural  agencies  which  produce  depressions  in  the  earth's  surface. 


I'oin-c'H.sions  on  now  land  area.  —  On  lands  recently  elevated  above 
the  sea  or  left  exposed  by  the  eva[)oration  or  drainage  of  inland  water  bodies, 
there  are  usually  inequalities,  and  \vater  frecpiently  collects  in  the  dei)res- 
sions  and  forms  lakes.  There  are  com})aratively  few  lakes  of  this  type  in 
North  America,  for  the  reason  that  large  portions  of  our  coasts  are  sinking 
and  new  land  areas  are  rare.  The  lakes  of  Florida,  however,  are  good 
e.vam[)les  of  this  class.  They  are  surrounded  by  marine  rocks  of  recent 
(-rigin.  and  are  but  slightly  elevated  above  tlie  sea.  In  fact,  all  of  the 
topograi)hic  features  of  Florida  indicate  inunaturity.  The  luxuriant, 
vegetation  of  the  southeastern  coastal  [)lain,  masks  the  slight  inecpialities 
of  the  surface,  and,  by  clogging  the  slack  drainage,  leads  to   a  greater 

1  Tliis  subject  has  hccii  discussed  liy  numerous  writers,  and  ]ias  led  to  controve.sies  not 
yet  ended.  Tlie  must  extended  and  most  sy.stemati;'  treatment  tiiat  it  l.is  received  may 
lie  found  in  an  essay  by  W.  .M.  Davis  "On  the  classification  of  lake  basins,"  in  Hoston 
Soc.  Xat.  Hist.,  rroc.  >ol.  til.  1HS2.  ji]).  :!  1  ">- .'iS I .  The  numerous  references  iriven  in  this 
paper  constitute  the  best  biblio<;rai)liy  of  the  subject  available.  An  imiiorlant  .supplementary 
pa[)er  by  the  same  author  is  republished  as  an  ap|ieudi.\  of  thi'  present  volume. 


LAKES   OF    NOUTH    A.MKltlCA. 


I'l'   ' 


!li' 


expansion  of  the  lakes  than  would  appear  if  tlie  land  was  barren.  The 
Avealth  cf  vegetation  tends  also  to  })reserve  the  orioiaul  harriers  fioni 
erosion.  Al)oiit  the  southern  shore  of  Hudson  hay  lliere  is  another  area 
reeently  ahandoned  hy  tlie  sea,  on  Avhieh  there  are  hdces,  hut  this  region 
is  so  little  known  that  it  eannot  he  jjointed  to  with  contideiiee  as  a  ease 
in  point.  •  In  the  Great  Hasin,  as  tlie  vast  area  of  interior  drainage 
l)etween  the  Sierra  Nevada  and  ]{oeky  mountains  is  termed,  there  are 
many  lakes,  some  of  them  of  large  size,  wliich  oeeui)y  depressions  in  tlie 
surfaces  of  sedimentary  deposits  left  exposed  hy  the  evaporation  of  much 
larger  Pleistocene  water  bodies.  Great  Salt  lake  and  Sevier  lake,  Utah, 
occupy  the  lowest  depressions  in  valleys  formerly  flooded  by  the  Avaters 
of  a  great  inland  sea  to  which  the  name  Lake  Bonneville  has  been 
ai>plit'd.  Pyramid.  Walker  and  other  Ldces  in  Nevada,  occur  in  valleys 
Avhich  are  deeply  filled  with  the  sediment  of  another  ancient  water  body 
named  Lake  Lahontan.  In  these  instances,  however,  and  in  many  others 
of  similar  character  throughout  the  Arid  Region,  the  positioiis  of  the 
present  lakes  on  the  apiiroximately  level  floors  of  desert  vallej's  have 
been  partially  determined  by  I'ecent  movements  of  large  blocks  of  the 
earth's  crust  adjacent  to  lines  of  fracture,  and  by  the  unecjual  deposition 
of  alluvial  material  swept  out  from  mountain  valleys  and  dei)osited  on  the 
adjacent  plain.  These  recent  changes  have  modified  the  character  of  the 
basins  now  occui)ied  l>y  lakes,  but  essentially  they  are  depressions  on  new 
land  areas,  and  form  the  most  typical  examples  of  their  class  that  can 
])c   found  in  this  country. 

There  are  irw  land  areas  about  the  borders  of  the  Laurentian  lakes, 
which  have  been  left  exposed  by  the  recession  of  still  greater  lakes  that 
occupied  the  same  basin  at  a  com[)aratively  recent  date,  and  also  in  the 
region  drained  by  Red  river  in  Minnesota  and  Canada,  formerly  flooded  a 
vast  lake  named  in  honor  of  F^ouis  Agassiz.  Along  some  of  our  rivers, 
also,  which  flow  through  ancient  valleys  now  deci)ly  filled,  there  are 
narrow  aieas  of  new  land,  similar  to  the  recently  ex[)osed  borders  of  the 
Laurentian  lakes.  In  all  of  these  instances,  however,  the  lakes  foimcd 
in  the  ine(]ualities  of  the  surface  are  small  and  of  little  importance. 

Lakes  on  new  land  areas  are  surrounde<l  l)y  toi)ographic  forms 
expressive  of  youth,  and  are  themselves  evideiice  of  topogra[)hic  im- 
maturity. When  drainage  is  estal)lished  on  such  areas  the  basins  are 
soon  emptied.  The  lives  of  lakes  of  this  class,  as  is  the  case  with  all 
terrestrial  water  bodies,  depend  largely  on  climatic  conditions.  Tliey 
may   continue    longer    in    one    region    than    in    another,    but    in    the 


i 

SUS]) 

^A 

tlie 

carri 

are  1 

- 

V. 

- 

cone 

1 

of   fl|(. 

\>VV1\   1 

OUliilN    Ol'    LAIvK    HASINS. 


8 


ere  are 
,  ill  the 
if  much 
!,  Utah, 
I  Avaters 
as  heeu 
valleys 
er  l)0(ly 
y  others 
,  of  the 
sys  have 
i  of  the 
^position 
(I  on  the 
r  of  the 
;  on  iie'.v 
that  can 

in  lakes, 

kes  that 

)  in  the 

)()(lo<l  a 

r  rivers, 

lere  are 

rs  of  the 

f()rmc<l 


ordinary  coui-se  of  topographical  devi'lopnieiit  are  transient  features. 
In  liuniid  regions  they  are  drained  more  (juieldy  tlian  wliere  tlie  rainfall 
is  small,  'i'hey  are  fresh  or  saline  according  as  they  overflow  or  are 
Avitliout  outlet. 

On  old  land  areas  where  the  streams  have  reached  maturity  or  old 
a^e,  the  inetjualities  of  the  surface  due  to  the  accidents  of  original  dejx)- 
sition  are  removed,  and  lakes  of  the  class  here  considered  are  ahsent. 
This  is  shown  in  a  striking  maimer  hy  contrasting  Florida  witli  the 
adjacent  Appalachian  region.  In  the  f(/rmer,  lakes  are  alnmdant,  and 
their  surroundings  give  almndant  evidence  of  recent  origin  ;  in  tlie  latter, 
the  topogra])hic  forms  as  Avell  as  the  terranes  from  whicli  they  have  been 
carved,  bear  the  stamp  of  antiquity. 

Lands  that  have  been  subjected  to  intense  glaciation,  or  have  re- 
ceived a  covering  of  glacial  deposit,  are  essentially  new  land  area,  and 
boar  evidence  of  to[)ogra[)hic  youth  ;  but  the  lakes  characteristic  of  such 
rejuvenated  lands  will  be  considered  in  advance  in  connection  with  other 
results  of  glacial  action. 

Itasins  due  to  atniosplioric  ajfencios.  —  The  "weathering  of  rock 
surfaces  progresses  unevenly,  on  account  of  varying  hardness  and  the 
varying  degree  to  which  they  yield  to  chemical  clianges.  This  is 
noticeable  particularly  on  granitic  areas,  as  granite  is  esi)ecially  prone  to 
disintegration,  and  produces  uneven  suifaces  Avhen  weathered.  The 
tendency  to  decay  unequally,  as  weathering  i)rogresses,  probably  exists 
in  all  rocks  ;  and  it  is  to  be  ex])ected  that  hills  and  hollows  wouhl  result 
for  the  action  of  the  atmosphere  on  any  variety  of  deposit,  es[)ecially  if 
marked  variations  occur  in  its  texture  and  composition.  This  tendency  is 
most  easily  detected  when  the  bedding  is  neaily  horizor.tal,  and  large 
sheets  of  nearly  level  strata  are  exposed  to  the  sky. 

The  products  of  weathering  are  removed  by  water  in  solution  and  in 
suspension,  and  are  l)lown  away  by  the  wind.  When  removed  by  water, 
the  formation  of  l)asins  is  checked  by  the  cutting  of  outlets.  When 
carried  away  by  the  wind,  depressions  known  as  "  wind-erosion  l)asins "' 
are  left.^  These  are  basins  of  excavation  or  true  rock  basins,  and  in  this 
respect  resend)le  dein-essions  eroded  ])y  glaciers.  Some  observers  liave 
concluded  that  many  of  the  rock  basins  connnonly  ascril)e(l  to  glacial 

'  Numerous  examples  of  sh.illow.  saucer-shaped  depressions  in  shale,  due  to  the  action 
of  the  wind  on  areas  hare  of  veijetation,  in  tlio  southeastern  part  of  (\>h)rado,  have  recently 
been  described  by  G.  K.  (iilbert.     .Tour,  of  Geol.,  vol.  il,  1805,  pp.  47-4». 


LAKKS    (»F    NORTH    AMEUICA. 


ilii:     ! 


ill  r 


1 1 


I'   I 


!     I 


I    !  I 


action,  are  wind  erosion  basins  or  areas  of  [)ronounee(l  rock  deeay,  from 
which  ghiciers  have  removed  the  h)osene(l  material  without  deeply  abraid- 
ing  the  uuweathered  rock  beneath.  The  mode  of  origin  of  rock-basins 
is  still  a  matter  of  controversy,  but  it  seems  evident  to  the  writer,  not 
only  from  I'eading  the  viirious  views  advanced  by  others,  Init  also  from 
personal  observation  in  many  lake  regions,  that  rock  basins  have  been 
forined  by  each  of  the  agencies  mentioned  as  well  as  by  a  combination  of 
the  two.  The  formation  of  basins  ])y  ice  erosion  and  by  chemical  solution 
might  be  included  among  the  results  of  atmospheric  action,  but  luider 
the  classification  here  adopted  they  fall  in  different  categories. 

Atmospheric  agencies  also  lead  to  the  formation  of  basins  by  depo- 
sition ;  as  for  example,  when  sand  is  drifted  into  dunes.  Drifting  sand 
freciuently  travels  across  the  country  for  scores  of  miles  in  the  direction 
of  the  prevailing  winds,  and  sometimes  obstructs  valleys  so  as  to  cause 
lakes  to  form.  The  best  illustration  of  this  occurrence  known  to  tlie 
writer,  is  in  the  central  part  of  the  State  of  Washington.  The  drainage 
of  one  of  the  deep  narrow  valleys  known  locally  as  "  Coulees,"  which 
trench  the  Great  Plain  of  the  C'oluml  ia,  has  been  obstructed  by  immense 
sand  dunes,  so  as  to  form  a  dam  and  retain  the  water  of  Moses  lake.^ 
Below  the  dam  of  drifted  sand  there  are  several  springs  fed  by  lake 
waters  percolating  through  the  obstruciion.  These  serve  to  keep  the 
v/atersof  the  lake  fresh.  'I'he  s])rings  below  the  sand  drifts  unite  to  form 
Alkali  creek,  which  in  winter  sometimes  has  sufTicient  volume  to  reach 
the  Columbia,  but  in  summer  suffers  from  evaporation,  and  terminates 
in  a  series  of  alkaline  pools. 

Drifting  sand  may  lead  to  the  destruction  of  a  lake  as  is  illustrated 
by  an  exami)le  in  western  Nevada.  The  branch  of  Truckee  river, 
supplying  Winnemucca  lake,  is  partially  obstructed  by  wind-blown  sand, 
and  a  struggle  for  supremacy  between  the  river  and  the  encroaching 
dunes  is  in  progress.  Should  the  sands  prevail  and  a  dam  be  formed, 
the  water  sui)ply  of  Winnemucca  lake  woidd  be  diverted  to  Pyramid 
lake,  and  its  basin  would  soon  become  desiccated. 

Volcanic  dust  is  carried  great  distances  by  air  currents,  and  might 
accunudate  in  a  valley  s(»  as  to  obstruct  its  drainage.  No  lakes,  retained 
by  dams  of  this  nature,  are  known  on  this  continent,  although  thousands 
(»f  square  miles  in  the  western  part  of  the  United  States  were  covered,  in 
Pleistocene  and  recent  times,  to  a  de})th  of  many  feet  Avith  fine  volcanic 

1  I.  C.  Kussell,  "Geological  Jieconnoissance  in  Central  Washington,"  U.  S.  Geol.  Siirv. 
Bulletin,  No.  108. 


OIJIGIN    OF    LAKIO    ItASINS. 


iiy,  il'om 
f  iilmiid- 
'k-l)iisiiis 
iter,  not 
[so  from 
ive  been 
lution  of 
solution 
lit  under 

by  de[)o- 
iuj;'  sand 
direction 

to  cause 
n  to  tlie 

drain  cige 
;,"  wliich 

immense 

ses  lake.^ 

by  lake 

keep  the 

;e  to  form 

to  reach 

erminates 

llusti'ated 
cee  river, 
)wn  sand, 
croachin']^ 
e  formed. 
Pyramid 

nd  mio-ht 
,  retained 
thousands 
overed,  in 
e  volcanic 

Geol.  Surv. 


dei)osit.s,  which  in  some  instances  have  assisted  other  agencies  in  pro- 
ducing inecpialities  of  the  surface. 

Itasins  <luo  to  aqin'cuis  a}f<'iu"ioM.  —  In  this  class  of  basins  tliere  are 
two  imi)ortant  sid)divisions  :  a,  basins  due  to  the  action  of  streams,  and 
/'.  basins  due  tc  tlic  action  of  waves  and  currents.  In  each  subdivision, 
but  more  especially  in  tbe  first,  there  are  basins  formed  by  excavation 
and  basins  due  to  deposition,  or  basins  due  to  destructive  and  to  construc- 
tive agencies.  Frequently  the  two  [jrocesses  have  united  in  the  foiiuation 
of  a  single  depression. 

ti.  JidxInH  fonniul  hif  streamx.  —  The  diainage  of  new  land  aieas,  es- 
j)ecially  in  huuiid  regions,  soon  oI)litcratcs  the  depression  due  to  the 
original  ineciualities  of  le  surface,  as  already  explained;  but  other  ba.sins 
resulting  from  the  actif)n  of  the  streams  themselves  are  formed. 

When  the  toi)ography  of  a  young  land  area  is  yet  immature,  and  more 
especially  when  the  elevation  is  considerable  and  tlie  climate  humid,  the 
even  flow  of  the  draining  streams  is  a])t  to  be  interrupted  by  rapids  and 
water-falls,  at  the  bases  of  which  excavation  is  accelerated  and  de|)iessions 
formed.  The  deepening  of  such  portions  of  stream-beds,  results  princi- 
pally from  the  friction  on  tlicir  bottoms  and  sides.  j)i'i)(incc(I  by  sand  and 
stones  moved  by  the  swift  currents.  Some  distance  below  falls  and 
ra[)ids.  the  current  usually  slackens,  and  the  waters  tleposit  a  portion 
of  their  load.  A  basin  of  this  character  is  now  being  excavated  below 
Niagara  falls,  and  other  examples  may  be  s-sn  in  the  channels  of  many 
mountain  streams.  Even  on  old  land  areas  like  the  southern  portion  of 
the  Appalachian  region,  where  the  streams  are  engaged  in  cutting  down 
synclinal  tal)le-lands  in  which  hard  and  soft  strata  alternate,  small  basins 
of  the  character  here  referred  to  are  of  common  occurrence.  Sliould  a 
stream  channel  in  which  such  inequalities  have  been  produced  be  aban- 
doned as  a  line  of  drainage,  the  1)asins  would  be  transformed  into  lakes. 

The  best  example  of  a  lake  basin  of  considerable  size  foimed  at  the 
base  of  a  water-fall,  that  has  come  under  the  writer's  notice,  is  in  the 
Grand  Coulee,  near  Coulee  City,  in  the  State  f»f  Washington.  The 
Columl)ia  river  now  skirts  the  northern  and  western  borders  of  the  vast 
lava-covered  region  known  as  the  frreat  Plain  of  the  Columbia,  or  more 
familiarly  as  the  "  I5ig  Bend  country,"  but  in  Pleistocene  times  its  })resent 
(U)urse  Avas  ol)structed  by  glaciers  which  descended  from  the  moiuitains 
to  the  north,  and  it  was  forced  to  cut  across  the  liig  Heiid  through  a 
series  of  deep  canons   in  the  lava.      Its  tempfirary  course  was   through 


.4 


6 


LAKEH    OF    NOKTII    AM  KKK  A. 


(Jniiid  C'oiilft',  iiud  near  (he  pivsciit  site  of  Couk't'  ("ity,  it  i>lun[^i'(l  dvcr 
ii  pi't'cipice  iilH)Ut  two  ImiidiL'tl  I'uct  liii,di,  und  foniu'd  a  cataract  of  tlic 
nature  of  Shoshone  falls,  Idaho,  hut  rivalinu^  Xianara  in  orandcur.  'l"\\o 
hasius  were  excavated  in  the  rocks  at  the  hase  of  the  falls,  which  wcic 
left  as  lakes  when  the  j^laciers  retreated  and  the  Columhia  returned  to  its 
old  channel.  These  lakes  still  exist  althoutjh  desert  shruhs  ^'row  on  the 
hrink  of  the  precipice  o\er  which  the  watei-s  of  the  flooded  and  ice-laden 
liver  previously  thundered.  Each  of  the  lakes  is  by  estimate  a  mile 
lont,''  and  half  a  mile  broad,  an.d  of  considi-rable  depth,  as  is  shown  by  the 
(hirk  blue  color  of  their  waters  when  seen  from  the  crest  of  the  encircling 
clitts.i 

The  deeper  positions  of  stream  channels  excavated  during  floods,  may 
be  transformed  into  lakes  when  the  waters  subside  or  when  the  course  of 
a  stream  is  cL.u.ged.  This  is  shown  by  the  temporary  i)onds  remaining 
in  many  humid  countries  during  droughts  when  water  no  longer  flows 
through  the  customary  surface  channels,  Imt  is  more  common  in  arid 
regions  where  the  streams  are  subjected  to  still  greater  fluctuations. 

'I'he  basins  just  deseiibed  are  formed  principally  by  excavation,  those 
noted  below  are  due  to  deposition. 

In  regions  of  rapid  erosion,  a  high  grade  and  conse(iuently  rai)id 
tributary,  may  bring  to  a  sluggish  trunk  stream  more  detritus  than  it  is 
able  to  carr}'  away.  When  this  happens,  the  main  stream  is  more  or  less 
c(»inpletely  obstructed,  and  lakes  may  result,  liasins  of  this  nature  occur 
in  the  steei)-walled  valleys  of  the  Sierra  Nevada  and  Rocky  mountains, 
and  are  to  be  expected  wherever  streams  have  cut  back  their  trenches  far 
into  an  u])land  and  receive  liigh-grade  tributaries. 

The  alluvial  cones  about  the  bases  of  moiuitains  in  the  Arid  Region 
are  frequently  several  miles  in  radius,  and  have  a  thickness  near  the 
mouths  of  the  gorges  from  which  the  material  forming  them  was  dis- 
charged, of  two  or  three  thousand  feet  or  more.  When  such  deposits  are 
formed  on  the  opposite  side  of  a  valley  only  a  few  miles  across,  they  may 
unite  one  with  another  so  as  to  form  transverse  ridges  and  give  origin  to 
basins.  Alluvial  cones  are  especially  conspicuous  in  regions  where  the 
drainage  in  the  valleys  is  weak  or  entirely  wanting,  thus  favoring  the 
f(n'mation  of  basins  in  the  manner  just  described.  Lake  Tulare,  in 
southern  California,  may  be  cited  as  an  example,  as  it  is  retained  on  a 
broad  alluvial  plain  by  material  swept  out  by  torrents  from  canons  in  the 

'  I.  C.  IJussell,  'Geological  Keconnoissance  in  Central  Washington,"  U.  S.  Geol.  Surv. 
Bulletin,  No.  108. 


I 


H 


have 

T 

cone 

■I 

worls 

bodi( 

of  ai 

1 

Rep., 

> 

OlllcaN    Ol'    LAKK    liASlNS. 


"(1  ovev 

of     till' 

Two 

•ll  Wi'W 

(1  to  its 
on  tho 

:^e-la(U'n 
a   mile 

1  by  the 

icircling 

)(ls,  may 
ouise  of 
niainin<>" 
er  flows 
in  arid 

IS. 

Ml,  those 

ly  rapid 
iiaii  it  is 
e  or  less 
no  occur 
)untains, 


[1 


ches  far 


I  Ke^ 

■ion 

near 

tlie 

was 

dis-          > 

)Osits 

are 

hey 

may 

origin  to 

here 

the         i 

iring 

the         1 

uhirt 

,  in         ^ 

led  on  a        ;i 

ns  in  the         ''■ 

Geol. 

Surv.         1 

Sierra  Nevada.  In  regions  where  tlu'  conditions  are  most  favorahki 
foi'  tlie  gidwtli  and  [(reservation  of  alluvial  cones,  there  is  hut  litth- 
rain-fall,  and  the  material  deposited  in  the  valleys  is  apt  (o  l)e  porous 
and  of  such  a  character  that  it  ahsorhs  water  ii-adily ;  for  this  reason 
lakes  may  he  absent  and  the  land  remain  desert-like  and  arid  although 
basins  exist. 

A  lack  of  close  adjustment  in  the  transjtorting  power  of  streams  may 
sometimes  he  observed  even  in  humid  co  ntrii-s,  and  in  regions  of  mild 
relief.  As  described  by  (t.  K.  Warren, ^  the  excess  <»f  material  brought 
l)y  ('hi[)peway  river  to  the  Mississippi,  obstructs  the  main  stream  so  a.s 
to  c-ause  an  expansion  of  its  waters  known  as  Lake  I'epin.  An  approxi- 
mation to  the  same  conditions  occurs  where  Wisconsin  river  and  Illinois 
river  join  the  "  Father  of  Water.s";  but  in  these  instances  it  is  only  in 
the  low  water  stages  that  the  ponding  becomes  conspicuous.  A  tendency 
in  the  same  direction  was  noted  by  J.  W.  Powell  while  making  his  ad- 
venturous journey  through  the  canon  of  the  Colorado ;  dangerous  rapids 
were  encountered  at  localities  where  lateral  streams  had  swept  debris  into 
the  main  channel. 

Perhaps  the  best  examples  of  lakes  held  by  obstructions  dej)()sited 
by  lateral  streams  that  can  be  cited,  occur  in  valleys  draining  to  the 
Assinil)()ine,  jNIanitoba.  The  lakes  referred  to,  are  situated  in  valleys  that 
Avere  cut  down  to  a  gentle  slope  when  the  abundant  drainage  of  glacial 
lakes  flowed  through  them  ;  but  the  weaker  modern  streams  are  unable 
to  maintain  such  a  faint  grade,  and  are  being  silted  up  where  tributaries 
enter.  Long  narrow  lakes  are  thus  formed  above  delta-fans  built  by 
streams  having  a  higher  grade  than  the  main  valley.^ 

The  .separation  of  lakes  lirienz  and  Thun,  Switzerland,  has  been  cited 
liy  Davis  as  an  example  of  the  partitioning  of  a  valley  by  the  union  of 
deltas  from  opposite  sides.  Interlaken  stands  on  the  beautiful  alluvial 
l)lain  thus  formed.  Several  other  similar  examples  in  central  Europe 
have  been  described  by  various  authors. 

Lakes  retained  by  the  dei)osits  of  lateral  streams  and  by  alluvial 
cones,  pertain  to  young  and  immature  streams,  and  are  incident  to  their 
work  of  ei'osion.  As  topographic  development  progresses,  these  water 
bodies  are  obliterated,  but  when  streams  reach  maturity  and  old  age,  lakes 
of  another  class  ajipear  along  their  courees.  ,  .. 

1  Am.  .lour.  Sci.,  vol.  10,  .'M  ser..  1878,  p.  420. 

-  Warren  Uphain,  "  Heport  on  Lake  Agas.siz,"  Canadian  Geol.  and  Nat.  Hist.  Surv.,  Ann. 
Rep.,  Tol.  4,  1888-89,  p.  22  B.  ,  -.,-. 


8 


LAKKS    OF   NOUTH    AMKUICA. 


In  th 


of  mature  sti 


that  Ii 


It  (1( 


th 


(I 


i-ti 


111  tlic  cose  ot  mature  streams  that  Have  eiu  down  me  seaward  portion 
of  their  valleys  nearly  to  hase-level,  that  is  aindoximately  to  the  level  of  the 
oeeaii,  and  where  rivers  risinj,'  in  mountainous  re^'ions  tlow  across  low 
plains,  it  freiinciitly  hapi)eiis  that  (lie  more  eiieifjfetii'  tributaries  towards 
tlicir  head  waters  bring  in  more  detritus  than  the  <»'ently  llowinj,'  trunk 
streams  are  able  to  carry,  and  de])osition  takes  i)lae(!  on  their  bottoms  and 
over  their  Hood  plains.  When  the  main  stream  is  floodcul  and  inundates 
its  valley,  its  load  is  dei)osited  most  abundantly  on  the  immediate  bordei-s 
of  its  t'hannel,  and  builds  up  lateral  embankments  (»r  levees.  When  this 
hai)[)ens,  the  latend  tiil)utaries  joining-  the  main  stream  in  its  lower  eoui-se, 
may  not  be  able  to  lill  up  their  valleys  as  rapidly  as  the  borders  of  tlie 
main  river  are  raised,  and  are  conse(piently  ponded.  Many  shallow  lakes 
have  been  formed  in  this  manner  along  the  borders  ol  the  large  rivers 
flowing  to  the  (Julf  of  Mexico.  The  most  eoiispicuous  examples  occur 
along  the  banks  of  I't'd  riv.'V,  Louisiana,  where  Literal  lakes,  as  has  been 
pointed  out  by  Davis,  are  arranged  along  the  side  of  its  levees  like  the 
leaves  on  a   twig. 

Ill  the  maturity  and  old  age  of  rivers,  when  they  meander  in  hroad 
curves  through  a  wide  Hood  plain,  as  in  the  case  of  the  lower  .Mississi[)pi, 
the  loops  are  frequently  cut  off,  as  shown  on  i'late  1,  and  erescent-sliapcil 
or  "ox-bow"  lakes  are  left.  Kxamides  of  lakes  of  this  chaiacter  on  a 
small  scale  may  be  seen  along  the  border  of  many  sluggish  Inooks  which 
traverse  deei)ly  filled  valleys. 

Ill  the  formation  of  low-grade  deltas,  like  those  now  in  process  of  con- 
struction at  the  mouths  of  the  Mississippi,  Nile,  Ganges,  etc.,  the  waters 
break  through  the  levees  of  the  main  stream  during  floods,  and  form 
branching  channels  or  "distributaries,"  which  in  their  turn  bifurcate  in  a 
similar  manner,  and  build  up  their  ehannels  and  inundated  borders.  In 
such  instances  low  areas  are  frequently  surrounded  by  embankments,  and 
left  as  basins  containing  shallow  lakes.  Many  examples  of  this  occur- 
rence are  found  on  the  broad  delta  of  the  Mississipi)i.  Of  these  Lake 
Pontchartrain  is  the  largest  at  the  present  time.  Lake  Rorgne,  in  the 
same  region,  is  another  exanqjle,  not  yet  completed.  The  delta  lands  of 
the  Khiiie,  in  Holland,  and  of  other  rivers  in  northern  Germany,  contain 
many  lakes  and  swamps  of  the  type  here  considered.  The  celebrated 
Zuyder  Zee  was  formed  in  part  as  a  delta  basin  and  in  part  by  the  con- 
struction of  natural  embankments  adjacent  to  a  low  sliore.  Miniatuiv 
illustrations  of  this  method  of  forming  l)asins  may  be  seen  on  the  delta> 
of  many  small  streams,  ])uilt  in  lakes  and  ponds. 


I 


I 


rd  portion 
nx'l  of  till! 
icross  low 
■rt  towiirds 
'n\\r  trunk 
ttonis  and 
innndatL's 
tii  bordem 
A'heu  this 
Viiv  I'oui'se, 
crs  of  tlu' 
How  lakus 
r^e  livi'is 
[ili's  ot'C'Ur 
s  has  been 
58  like  the 

r  in  broixl 
.lississi[)pi, 
L'nt^sliai)e(l 
actor  on  a 
)oks  whic'li 

■ess  of  con- 
tbe  Avators 
and  form 
urcate  in  a 
mlers.  In 
ments,  and 
this  occur- 
tliese  Lake 
rne,  in  the 
Ita  lands  of 
ny,  contain 
celebrated 
by  the  con- 
Miniature 
I  the  deltas 


L.VKKH  OK   NmiTI'    AMIIItrA. 


Pl.ATK   1. 


•  .^r" 


OX-BOW   LAKES,    LOWER    MISSISSIPPI. 


1 

i 

li 

i 

1! 

i 

i! 

OUKilN    OF    LAKK    IIASINS. 


9 


The  overloiuU'd  strciiins  from  ohicii-rs  mIs.)  fmiii  levees,  in  nuu'li  the 
Siiine  niiinner  us  in  the  ease  of  more  mature  streams,  'I'h'se  emliaiik- 
meiits  are  apt  to  Ik;  formed  of  hoth  coarse  and  tuie  material,  and  sometimeH 
enelrwe  low  ureas,  so  lus  to  ol»struet  their  drainage  and  give  origin  to  lakes 
and  ponds.  Young  streams,  on  account  of  the  an)ount  of  dehris  eon- 
triltuteil  to  them,  thus  in  some  instances,  simulate  to  a  certain  degree 
the  hehavi(U'of  more  mature  rivei-s.  Small  lakijs  of  the  class  here  ri'ferred 
to  occur  al)out  the  southern  Iiorder  of  the  Malasi»ina  glacier,  Alaska. 

h.  liitx'niH  f'linnrd  l>!i  inirrH  ami  runrntx.  —  Basins  a'e  fr»  (piently 
formed  along  the  ocean's  shore  and  on  the  lM)rder  of  lakes,  where  sand 
and  gravel  '»ars  have  heen  huilt  across  the  entrances  of  Uiys,  or  extend 
from  luailland  t<»  headland  so  as  to  cut  off  a  curve  of  the  shore.  Numer- 
ous examples  of  water  hodies  that  have  heen  isolated  in  this  way,  occur 
along  the  Atlantic  coast  and  ahout  the  shore  of  the  Laurentian  lakes. 
The  history  of  some  of  these  secondary  lakes  may  be  easily  read  from 
the  exceedingly  valuable  series  of  charts  published  by  the  II.  S.  Coast 
and  (ieodetic  Survey  and  by  the  U.  S.  Lake  Survey.  It  frecpiently  ha])- 
jjcns  that  lakes  separated  from  the  ocean  by  narrow  sand  bai-s,  are  fresh. 
This  is  due  to  tlie  fact  that  the  movement  of  water  through  the  shore 
deposits  is  from  the  land  seaward,  and  the  originally  saline  waters  in  such 
enclosures  have  been  flooded  out.  The  seaward  flow  of  underground 
water  also  exjjlains  why  fresh  water  may  be  obtained  in  wells  on  sand 
bars  of  the  character  here   referred  to. 

Besides  living  examples  of  the  chiss  of  lakes  liere  considered,  there 
are  basins  of  a  similar  origin  still  to  be  seen  about  the  borders  of  lakes 
that  have  ceased  to  exist.  In  the  Great  Basin,  and  esi)eeially  on  the 
bordei-s  of  the  valleys  formerly  tlooded  by  the  waters  of  lakes  Bonneville 
and  Lahontan,  there  are  small  lakes  and  enclosed  basins  not  now  flooded, 
which  are  due  to  the  formation  of  embankments  about  the  margin  of 
those  ancient  water  bodies.  The  valleys  formerly  covered  with  the 
water  of  these  great  seas  to  the  depth  of  many  hundreds  of  feet  are  now 
for  the  most  part  parched  antl  arid,  and  desert  shrubs  cover  the  em- 
bankments of  sand  and  gravel  on  v,  Inch  the  surf  formerly  broke.  Only 
a  few  of  the  secondary  basins  formed  along  those  ancient  shores  can  be 
referred  to  at  this  time. 

At  the  town  of  Stockton,  l^tah,  about  fifteen  miles  south  of  Great  Salt 
lake,  there  is  an  innnense  gravel  bar,  formed  near  the  highest  stage  of 
Lake  Bonneville,  which  sweeps  comi)letely  across  the  entrance  of  a  valley 
and  retains  the  waters  draining  from  the  southward,  so  as  to  form  Rush 


n     I 


1© 


LAKES    OF    NORTH    AMKIUCA. 


I    !i!ill 


ill! 


m 


i'i 


lake.  This  lake  is  variable  in  area  and  (le})tli.  Sometimes  it  measures 
two  and  one-half  miles  in  breadtli  and  is  about  five  feet  deep  ;  aq;ain, 
during  seasons  of  unusual  drouglit,  it  eva})orates  to  diyness.  Tlie  bar 
to  which  it  owes  its  origin  rises  one  hundred  and  fifty  feet  above  its 
surface,  and  under  more  favorable  climatic  conditions  would  retain  a  lake 
many  square  miles  iii  area.  The  view  of  the  great  bar  at  Stockton  and 
the  map  of  the  same  localitj^  presented  on  Plates  1  and  2,  are  so  graphic 
and  truthful  that  time  need  not  be  taken  to  des<;ribe  them. 

Another  ex.unple  <)f  a  lake  basin  formed  by  a  l)ar  crossing  the  entrance 
of  a  lateral  valley,  is  furnished  by  Lake  Annie,  near  Fort  Bidwell.  Cali- 
fornia. The  ancient  hike  on  the  l)order  of  winch  the  bar  now  retaining 
Lake  Annie  was  constructed,  flofxled  Surprise  valley,  in  the  nortlieast 
corner  of  California,  during  Pleistocene  times,  l)ut  is  now  represented 
by  eyceediugly  slialiow  alkaliiie  lakes.  Lake  Annie  is  a  few  liundred 
yards  in  diamcier,  and  is  ke})t  fresh  and  sweet  by  the  escape  of  its  surplus 
waters  tlu-ough  the  endtankment  retaining  it. 

Perliaps  the  l)est  of  all  the  examples  of  the  class  of  water  bodies  now 
under  consideration,  that  can  be  referred  to,  i.j  Humboldt  lake,  Nev.ada. 
This  lake  ()ccu[)ies  a  secondary  basin  in  one  of  the  valleys  formerly  flooded 
by  the  waters  of  l^ake  Lahontan.  When  the  ancient  lake  was  lowered  so 
as  to  approach  extiiiction,  a  bar  was  formed  directly  across  the  end  of  Hum- 
boldt valle}',  where  it  opens  out  onto  the  Carsen  desert.  The  w'aters  of 
Humboldt  river  were  retained  by  this  bar  when  Lake  Lahontan  fell  so 
as  to  leave  it  dry,  and  a  lake  formed  above  it.  The  waters  escaped  across 
the  bar  and  cut  a  channel,  s(,  as  to  partially  drain  the  l)asin  above;  but  in 
recent  years  an  artiticial  drain  has  l)een  constructed  in  the  opening,  and 
the  lake  now  covers  a  gi-eater  area  than  it  would  had  the  natural  con- 
ditions remained  unmodilied.  A  map  of  the  bar  retaining  HumboMt 
lake,  on  which  much  of  the  history  of  its  origin  can  be  read,  is  shown  in 
Plate4.i  .,-.  ^,^:      :  ■  :  .  "^'.^ 

Basins  ihw  to  }>rla('ial  apr<'iu'i<>s.  —  On  the  surfaces  of  glaciers,  esjie- 
cialiy  on  the  lo\\er  portions  of  n6\6  regions,  there  are  frequently  shallow 
depressions  holding  lakes  which  give  variety  and  an  additional  charni  to 
the. wintry  landscapes  with  which  they  are  surrounded.  No  ca.se  is  known 
in  which  these  lakes  are  })L'rennial,  although  they  foini  in  the  same  locali- 
ties year  after  yeai'.     'I'liey  ai'e  of  little  geological  interest,  for  tlie  reason 

1  I.  C.  Hussi'U,  "  (^UiUeniary  Ilistovy  of  Lake  Lahontan,"  U.  H.  Gt'ol.  Surv.,  Monograph 
No.  11. 


t 


I 


measures 
p  ;  aoain, 
The  bar 
above  its 
ain  a  lake 
skton  and 
so  graphic 

e  entrance 
well,  (-ali- 
'  retaining 
northeast 
spvesented 
,v  hundred 
its  surplus 

)()dies  now 
e,  Nevada, 
rly  flooded 
lowered  so 
id  of  Hum- 
;  waters  of 
tan  fell  so 
iped  across 
ve ;  but  in 
ening,  and 
itural  con- 
Ilunibohlt 
5  shown  in 


eiers.  espe- 
tly  shallow 
1  charni  to 
e  is  knt>nn 
anie  local  i- 
the  reason 

. ,  MuiiDgraph 


y.7^v 


■m: ; 


liv / -» /■ ' //// ; / ■  1 '  'I'll" 

##« 


./,!  i 
iV 


.a 
a. 
a 
u 
so 

2, 

o 


72 


cr 
m 

_j 


t 
< 


c/5 
< 

LU 


o 
o 


<  r: 

-  i 

<  9 

CO  S 


"    -I 

O       2 


O 


UJ 


!  i;r 


■_a.jujJiiiii.Miii.irmr-r  nnr 


immmm 


::i 


Bl 


OltlGIN    OF    LAKE    BASINS. 


11 


that  they  leave  but  slight  if  any  permanent  records.  Their  watera  are 
so  clear  that  practically  no  sediments  accumulate  in  them.  On  conti- 
nental glaciers,  however,  such  lakes  might  exist  from  year  to  year,  and 
perhai)S  receive  sufficient  tleposits  to  leave  recognizable  records  after  the 
ice  disappeared.  Certain  deposits  of  exceedingly  fine,  light  colored,  clay- 
like material  termed  loess^  in  the  upper  Mississipj)!  valley,  are  believed 
by  some  [)ersons  who  have  studied  them,  to  have  been  accumulated 
in  lakes  on  the  surface  of  the  great  ice  sheet  which  formerly  covered 
that  region. 

Wlicn  glaciers  flow  through  valleys  surrounded  by  mountains,  they 
sometimes  obstruct  the  drainage  of  lateral  valleys  so  as  to  cause  lakes  to 
form.  The  dams  in  these  instances  are  formed  by  the  ice  in  the  main 
valleys.  The  type  of  this  class  of  lakes  is  furnished  by  Miirjelen  lake, 
Switzerland.  In  this  instance  a  lateral  valley  l)elow  the  snow  line  is 
dammed  by  Aletsch  glacier  which  flows  past  its  mouth.  The  lake  is 
variable  in  area,  being  sometimes  a  mile  long  and  at  other  times  completely 
drained  owing  to  the  enlargement  of  the  tunnel  beneath  the  ice  dam 
through  which  it  discharges. 

In  Alaska  there  are  many  lakes  of  the  Milrjelen  type.  About  the 
southern  bases  of  the  foot-hills  of  Mt.  St.  Elias  there  are  several  water- 
bodies  that  are  held  in  check  by  the  Malaspina  glacier.  The  largest  of 
these,  known  as  Lake  Castani,  at  the  southern  end  of  the  Chaix  hills,  is 
two  or  three  miles  long  and  a  mile  broad  when  at  its  highest  stage,  and 
discharges  through  a  tunnel  eight  or  nine  miles  long,  beneath  the  ice 
sheet  to  the  south.  The  position  of  this  sulhglacial  river  can  be  traced 
by  a  depression  in  the  surface  of  the  ice,  and  when  above  it,  the  muffled 
roar  of  the  impri;-  ned  flood  can  be  heard  far  below  one's  feet.  Of  many 
lakes  similar  to  Lake  Castani  in  the  same  general  region,  perhaps  the  most 
instructive  is  one  discovered  by  John  Mnir,  in  Stikine  valley,  Britisli 
Columbia,  near  the  Alaskan  boundary.  In  this  instance  a  lake  about 
three  miles  long  and  approximately  a  mile  broad,  and  receiving  the  drain- 
age of  five  or  six  residual  glaciers,  is  held  in  a  lateral  valley  by  Toyatte 
or  Dirt  glacier,  which  flows  past  its  entrance.  The  outlet  of  the  lake  is 
tlu'ough  a  tunnel  in  the  ice,  which  is  sometimes  enlarged  so  as  suddenly  to 
cmi.ty  the  basin  and  cause  a  flood  in  Stikine  river.         ,  _    ..  i^.^-,  -. ..   - 

The  lakes  formed  when  glaciers  obstruct  the  drainage,  hre  variable 
■in  size,  owing  to  changes  in  their  draining  tunnels,  and  are  frequently 
emptied,  as  in  instances  just  cited.  The  surfaces  of  these  lakes  are  many 
times  'jovered  witli  floating  ice,  which  is  left  stranded  when  their  waters 


12 


LAKES    OF   NOUTH   AMKIMCA. 


i 


Mi 


escape.  They  are  unusually  turlnd  with  silt  ^wought  to  them  by  glacial 
stieams,  and  leave  inii»ortant  ^leposits  to  mark  tlieir  sites  when  the  condi- 
tions are  no  longer  favorable  to  their  existence. 

The  most  widely  known  example  of  the  formation  of  terraces  about 
the  borders  of  a  glacial-dammed  lake,  is  furnished  by  thf  Parallel  Roads 
of  Glen  Koy,  on  the  west  coast  of  Scotland.  The  origin  of  these  terraces 
was  a  fruitful  source  of  controvei-sy  for  many  yeai-s  ;  but  the  explanation 
that  they  are  clue  to  the  taction  of  the  Avaves  and  currents  of  a  lake  held  in 
a  lateral  valley  by  a  glacier  flowing  past  its  entrance,  has  finally  been 
accepted  as  satisfactory. 

It  is  wortliy  of  note,  that  lakes  of  the  type  just  desc-i'ibed,  not 
only  occur  in  mountain  valleys,  but  also  about  the  ends  of  mountain  spurs 
jtrojecting  int'i  encircling  ice  sheets,  as  on  the  northern  border  of  the 
Malaspina  glacier.  The  deltas  and  terraces  foimed  in  such  lakes  may 
remain  in  unexpected  places,  as  high  up  on  the  side  of  a  mountain,  whei; 
the  retaining  glacier  is  melted. 

When  the  land  bordering  an  ice  sheet  slopes  towards  tlie  ice,  the 
escape  of  the  waters  formed  l)y  the  melting  of  the  glaciei",  as  well  as 
streams  from  the  adjacent  areas,  is  checked,  and  margin-'.l  lakes,  some- 
times of  large  size,  are  foimed.  Two  small  examples  of  this  class  of 
Avater-bodies  were  seen  by  the  writer  at  the  northern  base  of  the  Chaix 
hills,  vVlaska.  During  tlie  close  of  the  (Jlacial  epoch,  Avhen  the  ice-sheet 
occupying  northeastern  North  America  was  retreating,  there  came  a  time 
when  the  southern  margin  of  the  ice  faced  a  northward-sloping  land- 
surface,  and  lakes  far  laiger  than  the  present  I^aurentian  lakes,  were 
formed.  The  largest  of  these  ancient  seas,  named  I>ake  Agassi/,,  covered 
the  region  in  Minnesota  and  Canada  now  drained  by  Red  river,  and 
otliers  were  formed  in  the  Laurentian  basin. 

AVhen  glaciers  melt,  the  rock  surfaces  left  exposed  are  frequently 
planed,  grooved  and  polished.  In  such  instances,  the  evidences  of  the 
friction  of  the  flowing  ice  and  of  the  sand  and  pebbles  frozen  into  it,  aiv 
])i'()nounced  and  unmistakable.  Tliese  marks  of  abrasion  are  frequently 
buried  and  concealed  by  deposits  of  debris  of  various  kinds  which  were 
transported  on  the  surface  of  tlie  living  glacier  o.  enclosed  in  its  mass, 
and  left  as  superficial  deposits  when  the  ice  melted.  In  the  lower  por- 
tions of  mountain  valleys  previously  occupied  b}'  ice  streams,  and  over  tin,' 
outer  b(U'der  of  regions  formerly  covered  by  continental  ice  sheets,  tlie 
deposits  of  d(?bris  are  in  many  instances  so  abundant  that  the  worn  rod; 
surfaces  beneath  are  completely  concealed. 


llii! 


iil 


hj  glacial 
the  coiuli- 

aces  al)out 
llel  Iloads 
se  terraces 
xplanatiou 
ike  held  in 
inally  been 

ci-ibed,  not 
ntain  spurs 
•dcr  of  the 
lakes  may 
utain,  when 

the  ice,  the 
,  as  well  as 
lakes,  some- 
lis  class  ol 
f  the  Chai\ 
the  ice-slieet 
i-ame  a  tinu 
loping  land- 
lakes,  wen 
ssiz,  eoveri'il 
d  river,  and 

e  frequent  1\ 
ences  of  tin 
.'11  into  it,  au 
•e  frequonth 
s  which  well 

in  its  mas-., 
le  lower  poi- 

imd  over  tlu' 
e  sheets,  tho 
he  worn  rock  | 


'^i 


if 
i 

'4 

■ill 


,1 


Lakes  of  'MoRTn  America. 


PlJlTE  3. 


MAP  HF  THE  PASS 
bet««en  • 

RUSH  AND  TOOELE  VALLEYS,  UTAH. 

showing  ihr 

WAVE  BUILT  BARRIER. 

By   H.  A.  Vrh«»l«r. 


M  A»  OwiwiFf. 


MM   0f  Jnr^mt     Chmuktt,     i^fiprvxf 


Vertical   Section  Trom  jc   to  KuBh   Lake 


STOCKTON    BAR     UTAH.     (AFTER   GILBERT.) 
Compare  viith  Plate  2. 


iHf 


■"•^s,. 


II, 


i 


m 


ORIGIN    OF   LAKE   UASINS. 


18 


The  study  Loth  of  livinpf  fjlaciers  and  of  the  vocords  left  hy  ancient 
■  glaciers  lias  proven  that  Howing  ice  both  erodes  and  dei)osits.  and  that 
!  basins  ivsult  from  each  of  tliese  processes. 

Wlietiier  a  ghicicr  shall  erode  its  beds  or  deposit  material  upon  it, 
bcems  to  de[)end  largely  on  it:'  grade,,  and  conse(inently  on  its  rate  of 
flow.  In  high-grade  valleys  among  mountains  forn)erly  occupied  by 
glaciers,  the  higher  and  steeper  portions  of  the  main  avenues  of  ice 
drainage,  are  usually  intensely  glaciated,  and  the  worn  and  rounded 
surfaces  are  frec^uently  bare  of  glacial  dei)osits  :  l)ut  the  lower  portions  of 
such  valleys,  especially  where  they  o})en  out  on  a  i)lain.  are  almost  always 
heavily  covered  with  morainal  material.  Not  only  are  moiaines  deposited 
in  the  mouth  of  the  valleys,  but  .sheets  of  gravel,  clay,  and  boulders  are 
spread  over  the  bottom  of  the  glaciated  troughs,  showing  that  the  iee- 
Streams  in  such  situations  deposited  material  on  the  surface  over  which 
Jhey  flowed. 

t.  Above  the  region  of  most  intense  glaciation  in  lofty  mountains  there  is 
zone,  embracing  the  higher  summits,  where  polished  and  scrattdied 
jBurfaces  are  rare,  and  where  there  is  but  little  debris.  This  ui)})er 
region  was  the  site  of  the  n6\-6s  or  snow  fields  of  t'^e  glaciei-s  that  abraded 
the  rocks  at  a  lower  horizon  and  deposited  their  loads  when  the  grade 
decreased  and  the  ice  currents  were  slackened.  A  similar  association  of 
region  of  glacial  abrasion  and  an  outer  zone  of  glacial  dei)osition,  may 
recognized  in  countries  formerly  covered  by  continental  ice  sheets.  In 
the  region  of  most  intense  glaciation,  in  the  case  of  both  Alpine  and 
fontineutal  glaciei-s,  as  has  been  shown  by  extended  observation,  there 
ii'e  numerous  rock  l)asins,  the  sides  and  bottoms  of  which  are  polished  and 
triated.  A  large  number  of  lakes  of  this  character  in  the  Cordilleran 
legion  have  been  examined  by  the  writer,  and  their  study  left  no  doubt 
tliat  they  were  due  to  glacial  action.  These  rock  basins  are  confined  to 
Weas  of  intense  glaciation,  and  are  absent  from  wljacent  areas  where 
the  conditions  are  essentially  the  same,  except  that  glaciers  have  not 
passed  over  them. 

It  is  impossible  to  point  to  examples  where  living  glaciers  are  actually 
engaged  in  wearing  out  rock  basins,  since  their  work  of  abrasion  is  neces- 
sarily concealed;  neither  is  it  possible  to  satisfactorily  observe  the  process 
T)y  whieh  glaciers  polish  and  striate  roi-k  surfaces,  yet  no  student  of  the 
subject  doubts  that  these  results  are  jtroduced  by  moving  ice  charged  with 
sand  and  gravel.  The  nature  of  the  evidence  leading  to  the  conclusion 
jat  many  rock  basins  are  due  to  glacial  abrasion,  is  of  the  same  character 


,oir 


14 


LAKi:S   OF   NORTH    AMEIIICA. 


mi 


iiii! 


as  the  evidence  from  wliich  it  is  coneludjd  that  many  smootlied  and  stri- 
ated rock  surfaces  are  due  to  the  same  agency.  The  rock  basins  of  tlic 
cliaracter  here  referred  to,  are  confined  to  regions  of  former  glaciation,  not 
only  in  America  but  on  other  continents,  and  are  wanting  where  other 
evidences  of  ice  action  are  al)sent.  The  interiors  of  tlie  basins  themselves 
are  smoothed  and  striated,  and  bear  incontestabhj  evidence  tliat  in  part  at 
least,  they  are  due  to  the  abrasion  of  sand-chai'ged  ice.  These  moic 
general  considerations  arc  in  sucli  harmony  with  what  is  known  of  tlic 
woik  of  ice  streams,  that  they  carry  even  more  weight  than  special 
studies  of  hidividual  lakes. 

Although  the  evidence  leading  to  the  conclusion  that  many  rock 
basins  in  glaciated  regions  are  essentially  of  glacial  <-rigin,  seems  to  the 
writer  to  be  conclusive,  it  is  but  just  to  state  that,  even  after  thiily  years 
of  ardent  controversy,  there  is  still  a  difference  in  o[)inion  among  geolo- 
gists and  others,  in  reference  to  the  abrading  power  of  nioving  ice,  and  its 
ability  to  erode  rock  hasins.  The  literature  bearing  on  this  question  is  so 
voluminous  that  it  is  impracticable  to  present  even  an  abstract  of  it  at  tbr 
present  time.^ 

\\'itbout  considering  further  the  results  of  the  destructive  action  of 
glaciers,  let  us  see  what  is  the  character  of  the  basin  they  produce  by 
construction.  Fortunately  in  this  connection  there  is  little  difference  dt 
opinion. 

The  terminal  moraines  left  by  Alpine  glaciers  in  their  retreat,  fre- 
quently form  crescent-shaped  piles  of  debiis,  convex  down  stream,  whi(  li 
act  as  dams,  and  retain  lakes.  Hundreds  and  })robably  thousands  ul 
exam[)les  of  lakes  held  in  check  by  obstructions  of  this  character,  exist  in 
the  valleys  of  the  Cordilleras,  and  are  common  in  every  formerly  glaciat(  il 
mountainous  region.  Tlie  Twin  lakes  in  the  Arkansas  vallev,  C'oloradn.- 
several  small  lakes  on  the  west  side  of  Mono  valley,  California,^  ami 
numerous  sheets  of  clear  water  in  the  Wasatch  mountains,  Utah,  so  well 
known  to  tourists,  are  types  of  this  class.     Similar  lakes  occur  about  tin 

1  This  subject  has  received  special  attention  since  the  appearance  of  a  celebrated  pnjn : 
by  Hainsay.  "On  the  glacial  origin  of  certain  Swiss  lakes,"  Quar.  .Jour.  Geol.  Soc,  vol.  1 
p.  ISo  ;  but  a  unanimous  conclusion  has  not  been  reachec  ,  .as  may  be  seen  by  consult  in. 
Nature  for  1803-04.     The  present  status  of  this  interesting  controversy  is  presented  in 
pajier  by  T.  G.  IJonney,  .and  accompanyiufi  discussions,  in  the  Geoj.n^'aphical  .Journal  of  '1; 
Hoyal  Geoffraphical  Society,  vol.  1,  18'.):>,  pp.  48l-o(M. 

•  F.  V.  Uayden,  U.  S.  Geol.  .and  Geoff.  Surv.  of  the  Territories,  Ann.  Hep.,  1S74.  p; 
47-;"):!.     .T.  .T.  Stevenson,  ICxplorations  and  Surveys  vrest  of  the  100th  Meridian  ("  Win  > 
Survey"),  vol.  :5,  1875,  pp.  441-444. 

8  I.  C.  Russell,  U.  S.  Geo!.  Surv.,  8th  Ann.  Uep..  188(1-87,  I'l.  .15.    '      ; 


I 

I 

I, 


■M 


I 


and  stri- 
iis  of  the 
ition,  not 
cvv  ntlu'i 
iiemst'lves 
in  part  at 
lese    more 
wn  of  tlif 
ui    spLH'ial 

many  i'<'*'l< 
i.nis  to  tlu' 
hii'ty  ytii^i'^ 
iiong  geolo- 
ici',  and  it> 
it'stion  is  SI 
:  of  it  at  til. 

vc  action  <> 
prodiK'e  It.v 
difference  of 

retreat,  fr>'- 

eam,  wliitli 

loixsands 
Lcter,  exist  in 

vly  glaeiatt'l 

y.  Coloradn.- 

iftn-nia,^ 

Utah,  so  u.'i 
cur  about  tlu 

celebrated  pap*' 
leol.  Soc.,vol.  1- 
een  by  consult  in- 
is  presented  in 
al  Journal  of  '' 

n.  IU'Pm  t«"^-  V 
eridian  ("  Wb" 


< 

< 
> 

uj" 
< 


O 

CQ 

Z) 
X 

a 
z 

z 

< 

H 
a: 

QC 

< 

Q3 


uJ 

> 
< 


>* 


'■<«*. 


OliKilN    OF    LAKK    UASINS. 


16 


extremitieH  of  the  existing'  {jfliiciei-s  of  this  country,  from  the  Hi^h  Sicini, 
Ciilifoniiu,  northward  to  Alaska.  'I'hese  arc  retained  liy  moraines,  from 
which  the  iee  has  reeeded  within  a  few  years,  thus  h-aving  not  even  the 
8ha(h)W  of  a  (h)uht  as  to  their  mo(U'  of  origin. 

Many  of  the  hikes  of  Scandinavia  and  of  Switzerland  are  retained  hy 
ancient  moraines,  as  are  also  in  part,  the  long,  deep  lakes  on  the  Italian 
side  of  the  Alps,  and  (haining  to  the  I'o.  The  most  striking  exami)le  of 
the  type  of  lake  here  descrihed,  however,  Avhich  has  l)een  studied  liy  the 
writer,  is  Lake  Wakatipu,  on  the  east  side  of  the  Soutiiern  Alps,  New 
Zealand.  This  magnilieent  water  body,  surrounded  on  all  sides  hy  lofty 
Bnow-cliid  jtcaks,  has  many  of  the  characteristic  features  of  lakes  Como 
and   .Miiggiorc,  and  is  not  second  to  them  in  majesty  and  hcauty. 

The  drainage  of  mountain  valleys,  in   which  moraine-ditmmcd  lakes 

Ihave  been  formed,  is  frecpieiitly  so  ahumhint  tliat  stream  channels  are  cut 

vMthrough  the   obstructions,   and  the  lakes  drained.      When   this  occurs, 

.Px^autiful  grass-covered  vales  or  "parks,"'  as  they  are  called  in  the  Rocky 

mountains,  are  formed.     These  charming  valleys  are  (juite  as  beautiful 

and  frcipiently  furnish  as  gi'cat  a  contrast  to  the  ruggcdness  of  the  sur- 

.rounding  scenery,  as  did  the  gem-like  lakes  that  i)ri'ce(le(l  them. 

In    most    instances    the    dcc[>    mountain   valleys   of    North   Ameilca, 
low   occupied   l)y  moraine-dammed    lakes,   were   excavated    by  streams 
jrevious  to  being  glaciated,  and  only  served  temporarily  as  avenues  for 
Ice  drainage.     Their  main  toi)Ograj»hic  features  are  due  to  stream  erosion 
M,nd  weathering.     Oiny  minor  changes  such  as  the  smoothing  and  round- 
ig  of  their  bottom  contours,  can  oe  ascribed  to  glacial  ii.l)rasion. 
%      The  general  sheets  of  debris  left  after  the  retreat  of  continental  glaciera 

tnd  by  the  melting  of  the  expanded  extremities  of  large  Alpine  glaciers, 
re  usually  uneven  on  account  of  the  manner  of  their  dei)osition.  and 
abounds  in  de})ressions  which  may  hold  water.  Jn  many  instances  the 
lakes  originating  in  this  manner  are  without  surface  outlets,  their  sur- 
plus water  escaping  by  percolation. 

I  (^n  the  formerly  ice-covered  itortion  of  nortlieastern  North  America, 
fhe  lakes  occupying  dejuessions  in  the  general  covering  of  superficial 
liaatcrial  are  so  numerous  that  the  position  of  the  southern  boundarv  of 
fte  old  ice  sheet  may  l)e  approximately  traced  on  a  diaiuage  map  of  the 
^giou  by  noting  the  southern  limit  of  the  lake-strewn  jjortion.  The  old 
land  surface  south  of  the  glacial  boundary,  is  almost  entirely  free  from 
uiidrained  basins  ;  <d  in  this,  as  well  as  in  other  respects,  presents  a 
striking  contrast  to  the   rejuvenated  surface   of  the   land  to  the  north. 


I" 


mmm 


16 


LAKIvS   OF    NOKTM    AMliUICA. 


Ii!!i 


ii!'^: 


The  lakes  occui»yinf:;  doprcsHioiis  on  the  ghicial  (hift  nmnhcr  IiutKhcds  of 
thousands.  Tlii'v  vary  in  size  from  mere  tarns  np  to  spU-niUd  watt"- 
slii't'ts  n>any  scjiiare  miU's  in  an  a.  !n  portions  of  Miinicsota,  Michi^nm. 
and  adjacent  areas,  whi-re  tho  drift  is  niiusnaliy  dL't'[»,  the  hdii's  in  irrcj^Mi- 
liir  depressions  on  its  snrface  sometimes  luimher  a  seore  or  more  to  th( 
wjnare  mih'.  It  is  estimated  that  in  Minnesota  alone,  there  are  not  U-ss 
than  ten  ilionsand  lakes  of  this  elass,  l)esides  many  swamps  and  marshes 
marking  the  sites  of  former  lakes  of  the  same  typ'e,  whieh  have  heeonie 
choked  with  vegetation. 

Nnnii'rons  lakt'sof  tiu^  same  charju'teras  those  on  t'"'  drift  of  \hv.  Nortli- 
eastern  Stales  and  Canada,  oeeni'  ahoiit  the  sonthei-n  margin  of  Maliispiim 
gla<  ier,  Alaska,  in  (h-pressions  in  moraines  left  hy  the  retreat  of  the  ice 
within  the  past  few  }ears.  These  very  modern  basins,  some  of  whieh  arc 
still  ocen[)ied  in  i)art  hy  the  ice  of  tho  retreating  glaeiei-s,  are  simihir  in  every 
way  to  the  basins  on  tiie  moraine-eovered  snrfaces  jnst  referred  to,  and  aiv 
snrronnded  by  topogrnphy  of  the  same  character,  thus  leaving  no  room  tnr 
donbting  that  each  of  the  two  series  is  due  to  similar  agencies. 

When  the  general  sheet  of  d(5bris  left  after  the  retreat  of  continent;il 
glaciers  does  not  completely  nuisk  tin'  pre-giacial  topography,  foinici 
Vidleys  are  sometimes  dammed,  ar.d  lakes  of  another  type  produced,  in 
many  instances  these  lakes  are  long  and  narrow,  and  indicate,  to  sonir 
extent,  by  their  form,  the  character  of  the  ancient  drainage  lines  tiny 
occupy.  Again,  they  may  be  broad  water-bodies,  and  occupy  ancieiii 
drainage  basins,  the  outlets  of  which  have  been  closed.  Pre-glaci;il 
valleys  may  be  deei)ened  hy  ice  erosions,  as  well  as  obstmeted,  and  tin 
two  processes  may  unite  v<)  form  lakes,  as  is  l)elicved  to  have  been  tin 
ease  in  the  group  of  "  '''ifi^,er  lakes  "  in  the  central  part  of  New  York  svatc' 

Still  another  type  ox  lake  basins,  due  to  glacial  agencies,  is  found  in 
unconsolidated  v  iter-laicl  material  ileposited  about  the  borders  of  ict- 
sheets.  When  the  stream-borne  ddbris  from  a  glacier  is  abundant  it 
forms  low  alluvial  cones  and  saiid  and  gravel  plains,  which  may  surro'uni 
or  cover  isolated  ice  masses.  When  such  buried  ice  masses  linally  nul- 
a  depression  is  left,  and  may  be  water-fdled.  The  boi'ders  of  su(  h  lal<r- 
are  of  loose  material  which  slides  into  the  depression  and  forms  sti  im 
banks.  The  inclination  of  the  enclosing  walls  depends  upon  the  natiii 
of  the  mr.terial  of  wdxich  they  are  composed.     Broad  tracts  of  sand  ini 

1  A.  P.  Britrlifiin,  "The  Finjier  lakes  of  New  York,"  Geop;raplucal  Soc.  Am.  Bull.,  v- 
26,  1803.  P..  S.  Tarr,  "  Lake  Cayuga  a  rock  basin,"  Geological  See.  Am.,  Bull.,  vol.  5,  l^i'i 
pp.  330-356 


vai 
poi-1 


i 


'"ff* 


01U(;iN    <>1"    I.AKK    ItASINS. 


17 


i\iuliv(ls  of 

(lid  watt'V- 

Miflii,!j;ini. 

^  in  inv^n- 

llOll!    to   111* 

n;  not  loss 
11(1  miirslK's 
ave  become 

f  llio  Novtli- 
if  Malii^l'iiiii 

t  of    lUe    if«' 

1)1'  wliicli  aiv 
lilar  in  overv 
lI  to,  autl  nil' 
r  no  room  for 

s. 

i  coutinont;il 
apliy,  t'oiiiHM 
vodiK'Otl-  111 
•ate,  to  soUH' 

trc!    linos    tluV 

cupy   aneieiu 
Pre-s^iiriM 
cted,  and  \h 
lavo  been  lli' 
sv  York  svati'.' 
■s,  is  fonnd  in 
)rders   of    i>'- 
abundant   i' 
may  suvvt>'uii'i 
es  finally  nul: 
of  sudi  lnl^»- 
il  forms  sttri 
on  tlie  natun 
of  sand  aii' 

Am.    Bull.,  ve. 
Bull.,  vol.  5,  IrfH 


gravi'l  with  liollows  of  tlic  character  just  descrilted,  .scattered  over  their 
Hurfaces,  are  known  as  "pitted  plain.s,"  and  tlnd  their  most  accept;'d)le 
exphmation  in  tht'  livpotliesis  just  su^'^'este<l. 

Lakes  Waldi'U  and  C'(»chitnate,  Massachusetts,  ari'  iKdiewd  to  he 
examph's  of  th(!  class  of  Ir.kes  here  referred  to,  aiid  to  (»\ve  their  orij,nn  to 
the  meltint,'  of  i(!e  ma.s.ses  that  were  either  jiartially  or  \vii(dly  buried  in 
gravid  and  .sand.'  Lakes  of  similai'  chanu'tci'  in  sonlhi'rn  Miehi<,'an, 
V.'here  glacial  de[)osits  are  unus\ially  alaindant,  mi<;ht  also  Im;  cited  in  this 
connection.  These  lakes  occupy  crater-shaped  deprt!ssions  in  tlie  snrfaeeH 
of  ;.,'ravel  and  sand  plains,  of  the  character  that  woidd  be  expected  to 
result  from  the  burial  and  snbsecpicnt  meltiui^'  of  ice  ma.sse.s,  in  the 
manner  outlined  above. 

Krom  this  brief  account  of  the  actioi;  of  ice  in  obstrnctinjx  drainajjfe, 
it  will  appear  that  lake  basins  are  formed  not  only  on  account  of  the 
danuninj^  of  streams  by  the  {iflacieis  themselves,  hut  by  jj^hu-ial  erosion 
and  j,''lacial  dei)osition ;  and  in  still  other  ways,  in  connection  with  tlio 
deposits  made  by  streams. 

ItasiiiN  due  t<>  voleniilc  afjeneies.  —  Ine(|ualities  on  tlic  surfaces  f)f 

lava  sheets  sometimes  giv;;  vi.se  to  lakes   in   nnich  the  same  manner  as 

lakes  are  formed  on  the  surface  of  glaciers.     Examples  of  such  basins  in 

'^various  stages  of  extinction,   by  drainage  and  sedimentation,  occur  on 

portions  of  the  lava  plains  of  Washington  and  Idaho. 

A  lava  stream  may  cross  a  valley  so  as  to  obstruct  its  drainage  and 
fl*ause  0  lake  to  form  above  it,  in  nnich  the  same  way  as  glacici's  dam 
"  iteral  valleys.  A  large  lake  was  formed  in  this  manner,  proljably  in 
'leistocene  times,  on  the  Yukon  river,  Alaska,  where  it  is  joined  by  Pelly 
liver.  A  series  of  lava  fli'ws  there  filled  the  river  valley  from  side  to  side 
ito  a  depth  of  several  hundred  feet,  and  formed  a  dam  which  retained 
tfihe  waters  of  the  Yukon,  and.  gave  v".rigin  to  a  broad  wattr-body  known 
jlw  Lake  Yukon.^  The  obstruction  has  aince  been  cut  through  along  the 
Southern  margin  of  the  old  channel,  leaving  a  series  of  btusaltic  precipices 
^D  the  right  bank  of  the  river. 

1  Warren  Uphain,  Bo.ston  Soc.  Mat.  Hist.,  Proc,  vol   2.').  pp.  228-242. 

^  W.  M.  Dawsoi:,  "  lleport  en  an  exploration  in  the  Yukon  district,"  Canadian  r-eol. 
^at.  Hist.  Surv.,  Ann.  Hep.,  1887-88,  p.  132  B. 

I.  C.  Rui»spn,  "Notes  on  the  surface  geology  of  Alaska."  G^ol.  Soc.  Am.,  Bull.  vol.  1, 
BOO,  pp.  14(1-148. 

C.  W.  Hayes,  "An  expedition  thro"gh  the  Yuk^^n  district^"  Natioaai  Geog.  Mag., 
1)1.  4,  1892,  p.  150. 


ii'ir 


.aimuiUiiLiiHTtilMIWili 


18 


LAKES   OF   NOUTH   AMERICA. 


Another  instance  of  the  fonnation  of  a  hake  on  account  of  the  filling 
of  a  valley  by  a  lava  flow,  hut  on  a  nuu'h  smallei'  scale  than  the  example 
cited  above,  has  been  observed  l)y  the  writer,  at  the  junction  of  Canadian 
and  Mora  rivers,  New  Mexico.  Canadian  river,  for  a  distance  of  perhaps 
a  hundred  miles,  flows  through  a  steep-walled  gorge,  in  which  for  a  space 
of  several  miles,  near  where  Mora  river  joins  it,  there  is  an  inner  gorge, 
as  .iidicated  in  the  following  cross  section  : 


Fio.  1.  — Cross  Section  nv  the  C'aSons  of  ('axahian  am>  :\Ioha  KrvEns,  New  MEXiro 

(J.  J.  Stevenson;. 


The  valleys  excavated  by  Canadian  and  Mora  rivers  were  filled  to  a 
de})th  of  400  feet  by  basalt,  as  indicated  by  vertical  lines  in  the  section, 
and  were  subseiiuently  eroded  to  a  depth  of  280  feet  deeper  than  before 
the  obstruction.  The  lake  v.hich  existed  above  the  lava  flow  has  been 
drained,  and  only  indefinite  traces  of  its  former  presence  now  remnin.^ 

Similar  instances  of  the  damming  of  streams  by  lava  flows,  are  known 
on  the  west  slope  of  the  Sierra  Nevada,  but  are  also  of  .ancient  date. 
The  lakes  that  were  formed  have  been  drained,  and  their  bottoms  trans- 
formed into  grassy  valleys. 

Two  small  lakes,  held  in  check  by  a  recent  lava  stream,  now  exist  at 
the  Cinder  cone,  near  Lassens  i)eak,  in  northern  California.  Beneath  the 
lava  retaining  these  lakes  there  is  a  sheet  of  fine  lacustral  marl  and  dia- 
tomaceous  earth,  showing  that  a  former  lake  was  partially  filled  by  thr 
molten  rock,  now  hardened  into  compact  basalt.^ 

Another  class  of  lakes  due  to  volcanic  agencies,  occupy  the  bowls  of 
extinct  cratei>!.  These  occur  in  various  situations,  being  sometimes  at 
the  summits  of  high  volcanic  cones,  and  again  in  depressions  in  broad, 
featureless  jjlains.  The  walls  enclosing  them  are  s;tmetinies  formed  of 
compact  lava,  but  more  fre(pi'}ntly  consist  of  scoria,  lapilli,  and  so-callcil 
ashes,  blown  out  of  volcanic  vents  during  periods  of  violent  eruption. 

1  Thi.s  instructive  locality  haa  beeii  described  by  .1.  J.  Ste.eiison,  in  Am.  Phil.  Soc,  Proc, 
1880,  pp.  84-87. 

"  J.  S.  Diller.  "  A  Late  Volcanic  Eruption  in  Northern  Celifomia. "  U.  S.  Geol.  Surv., 
Bulletin  No.  7y,  1891. 


ORIGIN    OF    LAKE    BASINS. 


19 


le  filling 
example 
Canadian 
;  perhaps 
•r  a  space 
ler  goi'ge, 


MEXiro 

filled  to  a 
l\e  section, 
ban  before 
\  has  l)een 
emnin.^ 
are  known 
cient  date, 
toms  trans- 

ow  exist  at 
beneath  the 
ivl  and  dia- 
lled hy  the 

le  bov.'ls  of 
(inetimos  at 
ns  in  broad. 
s  formed  ot 
ud  Ho-calk'il 
iiiptiou. 

Iiil.  Socl'iw  . 
S.  Geol.  Surv., 


At  Tee  Spring  buttes,  a  group  of  small  volcanic  cratei-s,  near  Fillmore, 
I'tah,  there  is  a  pool  of  water  in  the  throat  of  an  extinc^  volcano,  wliich 
()('cu[)ies  a  deiJiession  formed  by  tlie  recession  of  the  lava  that  once  rose  in 
and  partially  filled  tlie  crater.^ 

Tiie  Soda  ])onds  on  the  ('ai*son  desert,  near  Kagtown,  Nevada,  occupy 
lapilli  craters,  the  linis  of  which  rise  20  to  80  feet  above  the  surface  of 
the  adjacent  })lain.  The  larger  })ond  has  an  area  of  208  acres  and  a 
depth  of  147  feet,  and  its  surface  is  60  feet  below  the  general  level  of 
tlie  desert.^ 

A  crater  similar  in  character  to  those  holding  the  Soda  ponds,  occurs 
on  one  of  the  islands  in  Mono  lake,  California,  and  is  occupied  by  alkaline 
waters.  The  water  within  the  crater  stands  at  the  same  level  as  the  sur- 
face of  the  surrounding  lake,  a  connection  between  the  two  being  main- 
tained by  percolation  through  the  intervening  embankment  of  incoherent 
lapilli.3 

One  of  the  numerous  cratei-s  near  San  Francisco  peak,  Arizona,  is  said 
to  hold  a  lake  at  a  considerable  altitude  above  the  adjacent  country.  In 
the  summit  of  Mt.  Toulca,  ^Texico,  a  deep  depre.wion  produced  by  violent 
eruptions  is  stated  by  Davis  to  have  been  similarly  transformed. 

In  many  volcanic  regions  in  other  countries,  lakes  of  this  class  are 
known  to  occur.  They  aiC  common  in  Italy,  o>i  North  Island,  New 
Zealand,  and  are  reported  to  occur  in  the  Caucasus,  on  the  Solomon 
Islands,  in  India,  etc.  A  typical  example  of  a  water-filled  crater  is  fur- 
lushed  by  Lajij^her  See,  on  the  border  of  the  Eifel,  Germar.y,  and  lias  l)een 
described  and  illustrated  l)y  Edward  Hull.* 

Still  another  class  of  lakes  due  to  volcanic  agencies  occur  where  the 
summits  of  volcanoes  have  been  blown  away  by  the  energy  of  the  con- 
fined vapors  within  ;  or  when  the  base  of  a  volcanic  pile  has  been  melted 
so  as  to  cause  it  to  subside  into  the  conduit  from  which  the  material  com- 
posing the  mountain  was  extruded. 

It  is  believed  that  l)asins  have  resulted  from  each  of  these  processes, 
but  observations  on  their  actual  formation  are  lacking.  It  is  known, 
however,  that  volcanic  mountains  of  large  size  are  sometimes  literally 
blown  away,  as  happened  in  the  case  of  Krakatoa,  in  188(5. 

'  (J.  K.  Gilbert.     "  Lake  Bonneville."    IT.  S.  Geol.  Surv.,  Monofrraph  No.  1,  1800,  p.  :J22. 
-  I.  C.  Hussell.     "Lake  Lalxontan."     U.  S.  Geol.  Surv.,  Monof,'raph  No.  11,  1885,  pp. 
72-80. 

*  I.  C.  l{us.sell.  "Quarternary  History  of  Mono  Valley,  California."  U.  S.  Geol.  Surv., 
8th  Ann.  Rep.,  1880-87,  p.  ;173. 

♦  "  Volcanoes :  I'ast  and  l»rescnt."    Contemporary  Science  Series,  pp.  122-123, 


■r-^ 


w 


20 


LAKES    OF   NOKTH    AMElilCA. 


n 


In  several  volcanic  regions  there  are  deej),  circular  depressions,  known 
as  "  calderas  "  or  "  crater-rings,"  which  are  believed  to  have  been  formed 
by  the  blowing  away  of  the  mountains  tliat  once  existed  above  them.  A 
somev/hat  complete  series  can  1>3  established  between  craters  that  have 
been  pai-tially  broken  down  by  subsequent  eruptions,  and  crater-rings, 
about  which  there  are  in  some  instances  no  vestiges  of  the  oi'iginal  craters 
remainintj.  There  is  evidence  also  in  the  character  of  the  rocks  surround- 
ing  crater  rings,  and  in  the  adjacent  topography,  which  sustains  the 
hypothesis  of  their  violent  origin. 

Two  of  the  largest  calderas  yet  discovered,  occur  in  Italy,  and  are 
occupied  by  Lago  di  Bracciano  and  J>ago  di  Holsena.  As  described 
by  J.  W.  Judd,  the  first-named  is  nearly  circular,  Avith  a  diameter  of 
six-and-a-half  miles;  the  second,  somewhat  less  regvdar,  hfis  a  o-th 
from  north  to  south  of  ten-and-a-cpiarter  miles,  and  a  breadtii  of 
nine  miles.  The  only  examples  of  crater-rings  in  North  America 
that  can  be  referred  to  are  Gustavila  lake,  Mexico,  of  which  the 
wi-iter  has  been  unable  to  obtain  detailed  information,  antl  Crater  lake, 
Oregon. 

Crater  lake  has  been  described  by  C.  E.  Dutton,^  and  is  considered  l)y 
him  as  worthy  of  a  high  rank  among  tlifi  wonders  of  the  Avorld.  It  is 
situated  in  the  Cascade  mou  .tains,  in  northwestern  Oregon,  thirty  miles 
north  of  Klamath  lake,  at  an  elevation  of  G239  feet  al)ove  the  sea.  It  is 
nearly  circular,  Avithout  bays  or  prf)mont()ries,  as  indicated  on  the  accom- 
panying map,  Plate  5,  and  is  from  five  to  six  miles  in  diameter.  Tlie 
cliffs  of  dark  basaltic  rock  encircling  it,  I'ise  precipitously  to  heights  var}- 
ing  from  900  to  2200  feet,  and  nowhere  offer  an  easy  means  of  access  to 
the  basin  Avithin.  They  plunge  at  once  into  deep  Avater,  Avithout  leaving 
even  a  platform  at  the  Avater's  edge  Avide  enough  for  one  to  Avalk  on. 
There  are  no  streams  tributary  to  the  lake,  and  no  visible  outlet.  The 
Avaters  probably  escape  by  percolation,  as  the  precipitsition  of  tae  region 
is  in  excess  of  evaporation,  and  if  an  escape  Avere  not  furnished  the  babiii 
Avould  be  filled  to  overfloAving. 

Near  the  soutliAvest  margin  of  the  lake,  about  half-a-mile  from  shore, 
a  cinder  cone,  named  Wizard  island,  rises  from  the  Avater  to  a  height  »t 
645  feet.  This  cone  is  regular  in  form  and  has  a  depression  in  its  sum- 
mit, thus  showing  at  a  glance  that  :t  is  of  volcanic  origin,  and  is  in  fad 
a  miniature  crater  of  eruption.      From  the  base  of  Wizard  island  two 


1  Science,  vol.  7,  1886,  pp.  17t)-182. 
pp.  157-158. 


Also,  8th  Ann.  Rep.,  U.  S.  Geol.  Surv.,   1880-87, 


m 


T,AKFs  OF  North  America. 

tzris'  —10' 


423li: 


12ns 


k/stf 


CRATER   LAKE,   OREGON.     (AFTER  U.  S.  Geological  Survey.) 
Contour-interTal  200  feet ;  soiuidiugs  in  feet ;  lake  surface  (iiUU  feet  above  sea  level. 


Il'ff^ 


il 


i 


OIIIOIN    OB'   LAKE   BASINS. 


21 


streams  of  hardened  lava  extend  outward  towards  the  great  walls  enclosing 
the  lake,  but  do  not  reach  them. 

The  sounding  line  lias  shown  that  Crater  lake  has  a  maximum  depth 
of  2000  feet  and  is  the  deepest  lake  now  known  in  North  America  ;  its 
nearest  rival  being  Lake  Tahoe.  The  full  depth  of  the  basin  measured 
from  the  crest  of  the  enclosing  cliffs,  is  from  2i)00  to  4200  feet. 

The  rugged  slopes  encircling  the  lake  as  well  as  the  island  that  seem- 
ingly floats  on  its  jdacid  surface,  are  forest  covered,  thus  softening  and 
rendering  picturcscpie  the  otherwise  oppressive  grandeur  of  the  scene. 

More  remarkable,  however,  than  the  unicjue  scenic  features  of  Crater 
lake,  is  the  story  of  its  origin.  The  site  of  the  great  de[)ression  Avas  once 
occupied  by  a  volcanic  niountain  which  reached  far  above  the  highest 
point  on  the  cliffs  now  enclosing  it.  and  was  probably  as  conspicuous  a 
member  of  the  sisterhood  of  mountains  of  which  it  formed  a  part,  as  any 
of  the  neighboring  peaks,  but  the  once  prominent  i)ile  has  been  removed 
so  as  to  leave  the  profound  gulf  that  now  fascinates  and  stai'th;s  the 
observer.  The  character  of  the  sculptiuing  on  the  outer  sIojjc  of  the 
truncated  mountain  shows  that  it  was  eroded,  both  by  streams  and  by 
j  glaciers,  before  the  catastro[)he  that  carried  away  its  sunmiit  and  left  only 
a  hollow  stump  to  mark  the  site  of  the  ice-crowned  peak  that  formerly 
gleamed  in  the  sky. 

The  removal  of  the  summit  of  the  mountain  is  supposed  to  liave  been 
[due  to  a  mighty  explosion,  similar  to  that  which  ])lew  off  5000  feet  from 
[Krakatoa ;  or  else  that  the  mountain  was  melted  from  within  and  its 
[summit  engulfed  so  as  to  leave  the  depression  now  partially  filled  with 
[placid  waters.  Of  these  two  hypotheses,  the  second  seems  to  accord  best 
Iwith  the  observed  facts,  for  the  reason  that  fragmental  deposits  on  the 
svuface  of  the  adjacent  country,  of  the  character  that  would  be  exj)ected 
lad  the  sununit  of  the  mountain  been  blown  away,  have  not  been  recog- 
jized.  Subsequent  to  the  removal  of  the  sununit  of  the  mountain, 
•newed  volcanic  energy  of  a  mild  character  built  the  c  .iter-island  within 
|;lie  crater-rinsf. 

A  circi  lar  depression  in  but  little  disturbed  stratified  rocks  wliich 
cars  some  reseml)lance  to  a  crater-ring,  and  which  seems  likely  to  furnish 
le  key  to  the  origin  of  the  cable ras  of  Italy  and  other  regions,  lias 
jcently  been  discovered  in  Arizona,  about  25  miles  southeast  of  the 
)wu  of  Flagstaff.  This  unique  basin  has  been  carefully  studied  by 
i.  K.  Gilbert,  but  no  account  of  it  from  his  pen  has  come  under  the 
rriter's    notice.      The    observations    stated    l)elow   are    mainly  from  a 


*>o 


LAKES   OF   NOUTH   AMERICA. 


i|';:|;M; 


M 


description  of  a  model  of  the  locality  published  in  the  American 
Geologist.^ 

This  "  crater "  in  what  is  known  as  Coon  butte,  is  three-fourths  of  a 
mile  in  diameter  and  its  l)ottom  is  depressed  from  500  to  {WO  feet  below 
the  encircling  rim,  which  rises  1  50  to  200  feet  above  the  surrounding 
plains.  The  surface  limestone  of  the  region,  elsewhere  horizontal,  is 
steeply  inclined  quaquaversally  in  the  cliffs  around  the  crater ;  and 
masses  of  the  samn  stratum  and  of  an  underlying  sandstone,  are  strewn 
in  irregular  profusion  outward  from  the  crater  to  the  base  of  the  butte, 
which  has  a  diameter  of  about  two  miles.  In  leps  amount,  the  same 
debris  reaches  outward  on  all  sides  over  a  nearly  circular  area  to  a 
distance  of  about  four  miles.  No  lava,  bombs,  lapilli,  or  other  vol- 
canic products,  Avere  seen.  The  formation  of  this  irregular  crater-like 
de})ression  is  referred  by  Ciilbert,  perhaps  provisionally,  to  a  steam 
explosion. 

The  occurrence  in  the  vicinity  of  Coon  butte  of  hundreds  of  fiag- 
ments  of  meteoric  iron,  up  to  about  a  pound  in  weight,  and  of  several 
l)ieces  weighing  from  20  to  600  pounds,  led  at  first  to  the  thought 
that  possibly  a  meteorite  of  great  size  might  have  struck  this  spot,  buried 
itself  out  of  sight  and  thrown  up  a  crater-like  rim.  This  hypothesis, 
upon  being  tested,  was  abandoned,  however,  because  the  volume  of  the 
raised  rim  and  of  the  rock  fragmentb  scattered  about,  was  found  to  corre- 
spond very  closely  Avith  that  of  the  depression  below  the  level  of  the 
plain  :  and  for  the  second  reason,  that  a  magnetic  survey  failed  to 
indicate  the  existence  of  any  large  mass  of  meteoric  iron  competent  to 
make  such  a  crater,  within  at  least  a  depth  of  many  miles.  This  second 
objection,  however,  is  now  considered  of  but  little  weight,  since  the 
meteoric  fragments  found  about  the  crater,  although  now  magnetic, 
have  undergone  alterations  of  a  character  which  seem  to  indicate  that 
when  they  first  reached  the  earth  they  might  not  have  had  any  or  but 
slight  magnetic  properties.  The  changes  produced  in  the  surface  frag- 
ments are  due  to  atmospheric  influences,  which  would  not  reach  a  deeply 
buried  body. 

The  crater-like  depression  in  the  summit  of  Coon  butte  is  without 
water,  for  the  reason  that  it  is  situated  in  an  arid  region,  but  under 
humid  skies  would  no  doubt  be  transformed  into  a  lake. 

The  only  counterpart  of  Coon  butte  as  yet  discovered,  is  situated  in 
the  central  part  of  the  Peninsula  of  India,  some  200  miles  northeast  of 

1  Vol.  18,  1894,  p.  115. 


'IW6 


OIMGIN    OF   LAKE   UASINS. 


M 


Bombay.  Tliis  remarkable  crateriform  lake,  known  as  Lonls  lake,  is 
described  by  K.  I).  Oldbam  ^  as  follows  : 

"Tlie  surrounding  country  for  bundreds  of  miles  consists  entirely  of 
Deccan  tra[»,  and  in  tliis  rock  tbere  is  a  nearly  circular  hollow,  about  800 
to  400  feet  deep  and  rather  more  than  a  mile  in  diameter,  containing  at  the 
bottom  a  shallow  lake  of  salt  water  without  any  outlet,  whose  waters 
deposit  crystals  of  sesquicarbonate  of  soda.  The  sides  of  the  hollow  to 
tlie  north  and  northeast  are  absolutely  level  with  the  surrounding 
country,  while  in  all  other  (bisections  theie  is  a  laised  rim,  never  Acced- 
ing 100  feet  in  height  and  fretiuently  only  40  or  oO,  composed  of  blocks 
of  basalt,  irregularly  piled,  and  [)rt'cisely  similar  to  the  rock  exposed  on 
the  sides  of  the  hollow.  The  dip  of  tlie  surrounding  traps  is  always 
from  tlie  hollow,  but  very  low. 

"It  is  dillicult  to  ascribe  this  hollow  to  any  other  cause  than  volcanic 
explosion,  as  no  such  excavation  could  be  produced  by  any  known  form 
of  afpieous  denudati(tn,  and  the  raised  liin  of  loose  blocks  around  the  edge 
appears  to  preclude  the  idea  of  a  simple  depression.  It  is  true  that  there 
is  no  sign  of  any  eruption  having  accompanied  the  formation  of  the  crater  ; 
no  dyke  can  be  traced  in  the  surrounding  rocks  ;  no  lava  or  scoria'^  of  later 
age  than  the  Deccan  trap  period  can  be  found  in  the  neighborhoo(..  The 
raised  rim  is  very  small,  and  cannot  contain  a  thousandth  part  of  the  rock 
ejected  from  the  crater,  but  it  is  imi)ossil)le  to  say  how  much  was  reduced 
to  fine  powder  and  scattered  to  a  distance,  or  removed  by  denudation. 

"  Assuming  that  this  extraordinary  hollow  is  due  to  volcanic  explosions, 
the  date  of  its  origin  still  remains  to  be  determined.  That  this  is  long 
posterior  to  the  epoch  of  the  Deccan  traps  is  manifest,  for  the  hollow 
appears  to  have  been  made  in  the  present  surface  of  the  country,  carved 
out  by  ages  of  denudation  frcnn  the  old  lava  flow.  To  all  ai)pearauce 
the  Loiuts  lake  crater  is  of  comparatively  recent  origin,  and  if  so  it 
suggests  that,  in  one  isolated  spot  in  India,  a  singularly  violent  exfJosive 
acti(m  must  have  taken  place,  unaccompanied  by  the  eruption  of  melted 
rock.  Nothing  similar  is  known  to  occur  elsewhere  in  the  Indian 
Peninsula." 

Besides  the  obstructions  to  drainage  produced  by  overflows  of  lava, 
and  by  volcanic  explosions,  it  may  also  be  not'l  that  volcanic  dust  and 
ashes,  ejected  from  volcanoes  during  times  of  violent  eruptions,  may  be 
deposited  over  the  adjacent  country  in  such  a  manner  as  to  choke  the 
streams  and  possibly  form  dams  which  would  retain  lakes.  This  process 
»  "  A  Manual  of  the  Geology  of  India."  2(1  ed.  Calcutta,  18!t:].  pp.  19,  20. 


a: 


ill 


lliil  ;i: 
1  III     lis: 


ll 


24  LAKES   OF   NORTH   AMEUICA. 

has  already  been  referred  to  ia  connection  with  the  formation  of  1)asins 
through  the  action  of  eolian  agencies. 

Lava  streams  frequently  cool  on  the  surface  while  the  liquid  rock  below 
is  still  flowing.  In  such  instances,  when  the  crust  is  sulliciently  strong 
to  sustain  itself,  the  molten  lava  beneath  flows  out,  leaving  caverns. 
Openings  of  this  nature  may  become  water-filled  and  form  subterranean 
lakes,  or  their  roofs  may  fall  in,  leaving  depressions  open  to  the  sky. 
Lakes  and  ponds  occupying  such  depressions  are  thought  to  exist  on  tlic 
vast  lava  sheets  of  Oregon,  Washington  and  Idaho,  but  clear,  simple 
exam[)les  of  the  type  are  not  at  hand. 

On  a  small  lava  flow  on  an  island  in  Mono  lake,  California,  there  aic 
depressions  occupied  in  part  l)y  water,  which  are  due  to  a  general  sul)- 
sidence  of  the  surface  on  account  of  the  outflow  of  molten  rock  below  and 
the  crumpling  of  the  crust  into  concentrir,  crescent-shaped  ridges. 

Another  mode  in  wliich  volcanic  agencies  may  produce  depressions  is 
by  subsidence  of  the  surface  about  volcanoes,  due  to  the  removal  of  lava 
from  subterranean  reservoirs,  but  no  instances  where  this  has  certainly 
occurred  have  yet  been  observed  in  this  country. 

Ilasiiis  due  to  the  iir  .ict  of  meteors.  —  The  study  of  the  origin  of 
the  crater-like  forms  on  the  surface  of  the  moon  recently  made  by  Gilbert.' 
was  suggested  by  the  hypothesis  that  depressions  on  the  earth's  surface 
might  result  from  the  impact  of  meteoric  bodies.  This  suggestion  has 
already  been  referred  to  in  describing  Coon  butte,  and  is  one  of  great 
interest.  Up  to  the  present  time,  however,  no  basins  on  the  eartli's  sur- 
face are  known  which  can  be  ascribed  to  this  agency. 

If  the  earth  was  formed  by  the  coming  together  of  a  large  number  of 
previously  independent  meteoric  bodies,  as  is  thought  to  have  been  tlie 
case  by  Lockj-er,  all  evidence  of  such  an  occurrence  in  the  relief  of  its 
surface  is  wanting.  Small  meteors  are  known  to  reach  the  earth  every 
day,  and  a  number  have  been  discovered  weighing  many  tons,  but  suth 
an  event  as  the  earth  coming  in  contact  witli  a  planetary  mass  a  mile  i»r 
several  miles  in  diameter,  as  seems  to  have  lia^jpened  in  the  case  of  the 
moon,  is  not  only  unrecorded  in  history,  but,  as  just  stated,  there  is  w 
evidence  in  the  surface  features  of  the  earth  to  show  that  such  :ui 
event  has  happened  in  recent  geological  time.  If  the  earth  once  had 
a  pitted   surface,    like    the   moon,   and  was  scarred   b}'  vast  crater-like 

i"The  Moon's  Face,"   I'hilosophical  Society  of  AVashiiigton,  Bull.  vol.  12,   1803,  pr   -| 
241-292. 


ORIGIN   OB'    LAKE   IJASINS. 


25 


.ear,  simple 


depressions,  each  one  the  record  of  the  piercing  of  its  surface  and  the 
hurial  within  its  crust  of  a  planetary  mass  previously  rcvolvinfi;  independ- 
ently in  space,  the  date  of  the  last  of  the  catastroi»hes  which  produced 
that  condition  must  hf,ve  heeii  so  remote  that  erosion  has  removed  all 
surface  evidence  of  the  fact.  Still  farther  negative  evidence  may  he  cited, 
inasmuch  as  no  buried  meteoric  masses  recognized  as  such,  have  been 
found  in  the  rocks  now  forming  the  earth's  surface.  This  is  r.ot  proof, 
however,  that  the  meteoric  hyi)othesis,  as  applied  to  the  earth,  is  not  true, 
as  the  main  events  in  that  drama  are  assumed  to  have  been  enacted  befo"o, 
the  formation  of  the  stratilied  locks  now  recognizable. 


krol.   12,   1893,  m' 


Basins  due  to  cnrtliqiiakcs.  —  During  earthquakes  there  are  undula- 
tions of  the  surface  of  the  regions  aftected  which  sometimes  produce  pei- 
inaiient  elevations  and  depressions  and  thus  affect  the  drainage.  The 
passage  of  earthquake  waves  through  loose  deposits  may  cause  them  to 
become  more  compact  and  perhaps  jjioduce  depressions  on  their  surfaces. 
In  these  and  probably  other  ways,  basins  may  be  formed  by  eartluiuakes 
and  give  origin  to  lakes. 

The  best  examples  of  lake  basins  in  America,  resulting  directly  from 

eartlujuake  shocks,  occur  in  what  is  known  as  the  "Sunk  country"  in 

i southeastern   Missouri  and  northeastern   Arkansas.     A   series  of  severe 

disturbances,  known  as  the  New  Madrid  eartliquake,  affected  that  region 

between  1811  and  1813,  and  caused  both  elevations  and  dei)ressions  in 

the  forest-covered  flood  jjlain  of  the  Missi.s.sip[)i.    This  region  has  recently 

[been  examined  by  W  J  Mc(tee,^  who  reports  that  a  low  dome  some  20  miles 

in  diameter,  was  upheaved  athwart  the  course  of  the  ^Mississippi  and  that 

[the  river  was  held  in  check  for  a  brief  period,  but  soon  cut  a  channel 

[through  the  obstruction.     An   adjacent  area  some   one  hundred  square 

[miles  in  area,  was  de[)iesse(l  and  is  still,  in  i)art,  occupied  by  lakes  in  which 

the  trunks  of  trees  killed  by  the  inundation  are  standing. 

During  eartlKpiakes  in  regions  occupied  by  unconsolidated  rocks, 
ater  is  sometimes  forced  to  the  surface  with  great  violence,  probably  on 
iccount  of  the  compression  of  porous,  water-charged  strata,  and  lises 
l^ountain-like  above  the  surface.  The  water  brings  with  it  quantities 
)f  sand  and  mud  which  are  deposited  around  the  points  of  discharge  and 
kerve  to  enlarge  the  depressions  produced  by  the  violent  outrush.  When 
fountains  cease  to  play  these  small  cratei-like  basins  remain  as  ponds. 

1  "A  Fcssil  Earthquake,"  in  Geol.  Soc.  Am.,  iJull.,  vol.  4,  pp.  411-415. 


■r- 


26 


LAKKS    OF    NOUTM    AMKIMCA. 


Itasiiis  duo  to  orf^aiiii-  ajf<*i"«'i<'f*.  —  The  study  uf  coral  reefs  lias 
shown  that  bodies  of  sea  water  are  soiuetiiiU'S  cut  oft'  from  the  ocean. 
althou<^di  rarely  coin|)letely  se])arate(l,  hy  the  j,'rowth  of  reefs  of 
liviiiLj  coral  adjacent  to  coasts,  or  as  atolls  about  isolated  islands  and 
"banks."  liakes  of  this  nature  perha[)s  occur  at  llie  south  end  of  Florida, 
and  on  the  West  India  islands,  but  no  well  delined  instances  have  been 
described. 

The  formation  of  peat  in  temperate  latitudes  rffords  another  illustra- 
tion of  the  mannei-  in  whicli  orjijauic  agencies  lead  to  tlie  formation  of 
lakes.  The  growth  of  the  moss  known  as  Sjihai/nuiit,  from  which  peat  is 
largely  formed,  may  ()l)struct  sluggish  drainage  ;  and  its  une(|ual  growth 
in  swampy  areas  leads  tf)  the  formation  of  mounds  with  dei)ressions  in 
their  sununits.  '1  he  best  known  illustration  of  this  type  is  Drummond 
lake,  in  Virginia,  but  many' smaller  examples  occur  in  other  swampy 
areas.  It  has  been  suggested  that  the  basins  in  peat  swain})S  may  havt' 
originated  by  the  burning  of  the  bogs  during  times  of  excessive  drouth. 
That  this  might  happen  is  evident,  but  no  authentic  case  of  such  an 
occurrence  is  known  to  the  writer. 

On  the  vast  tundras  skirting  the  Arctic  ocean  in  both  the  Old  and 
the  New  World,  there  are  vast  numbers  of  ponds  and  lakes  held  in 
depressions  in  the  frozen  bogs,  and  surrounded  by  banks  of  moss  and 
other  vegetation.  These  water-bodies  have  probably  originated  in  various 
ways,  but  in  some  instances  their  birth  may  be  traced  to  the  luxuriant  | 
growth  of  vegetation  in  s})ring  and  early  summer  about  the  borders  of  "j 
liuLferiufj  snow  banks.  When  the  vegetation  of  the  tundras  awakens 
after  its  long  winter  sleep,  its  growth  is  sur])risingly  rapid,  and  the  snow 
drifts  that  last  longest  are  surrounded  with  luxuriant  mosses  and  brilliant 
flowers.  When  such  accunudations  of  snow  finally  melt,  the  vegetation 
on  the  areas  they  occupied  is  less  in  amount  than  on  the  surroundinu-  | 
surfaces.  The  tundra  increases  in  depth  by  the  partial  decay  an<l 
freezing  of  the  lower  portion  of  the  vegetation  forming  its  surface,  ami 
the  greatest  thickness  of  frozen  soil  occurs  where  the  vegetation  is  most 
luxuriant.  For  these  reasons,  the  places  where  snow  banks  form  year 
after  year,  become  depressed  in  reference  to  the  general  surface,  and  giM' 
origin  to  lakes. 

In  sulvArctic  regions,  as  on  the  Aleutian  islands,  mosses  ami 
herbaceous  vegetation  grow  luxuriantly,  and  among  the  hills  sometiniis 
obstructs  the  drainage  by  reason  of  the  formation  of  a  deep  peaty  soil  In 
its  partial  decay. 


1  reefs  1ms 
the  oceiiii, 
f  reefs  of 
isliuuls  iuul 
[  of  Florida, 
!  have  been 

her  illusti-ii- 
uiinatioii  of 
hich  peat  is 
iiual  gi'owtli 
press  ions  in 

Drummond 
her  swampy 
ps  may  have 
ssive  drouth. 

of  sueh  an 

the  Ohl  and 
kes  heUl  in 
of  moss  and 
ed  in  various 
he  hixuriant 
e  borders  of 
h'as  awake  n^ 
ind  tlie  snow 

and  brilliant 
lie  vegetation 

surroundin.;' 
il  decay  an<l 
I  surface,  and 
[ition  is  most 
iks  form  year 
:ace,  and  gi^^ 

mosses    ami 

ills  sometimt'^ 

peaty  soil  by 


k .  f  •  r//^(^ '/ ilk 


M 


1  /', 


w;i» 


/i'/'i 


a' 


1"!  < 


f 
s 

s 

-M 

s 

V 


ir'riiii.'«»iM,iil  ^MWJMMI— Ml 


I 


'1^ 


'iSiiii 
ilill 

1 

I 

hi 


Eofnc 


OKKilN    OF    I.AKK    HASINS. 


27 


Heiiver  diuns  iifToid  still  iiiiotluM-  illu.stniti»tn  of  the  iniiiintT  in  wliifli 

(Iraiiiag*!  is  (.'wtriictt'il  iind  lakt's  IoiiiumI  l»y  <>i';,'aiii('  a<f<'iicios.      lii-avci-M 

formerly  lived    (»V('r  iioarly  l!»e  wlHtlc  of    North   Aniciica,  and  an;  still 

found  in  limited  nnmlicis  in  the  Northern  states  and  Canada,  and  extend- 

\\U'^  s(i\ith\vard  alont;  the  Cordilleras  at   least  as  far  as  New  Mexico.      Tlie 

(lams  they  constructed   with    j^reat   intelli,t,'enee  and    skill,   across    small 

Islreanu'-    retained    diift    lojj^s    and    lloatin^f    leaves,  thus    leading'    to  the 

laeeuinulatioM  of  deposits  which  ohstructed  the  drainaj^e  foi'  a   lonj^  time 

laflcr  they  had   heen   aliandoncd  hy  the   animals  that   huill  them.     'I'he 

ponds  luid  swamps  due  to  the  work  (»f  heaveis  nnmher  tens  of  tlunisands, 

md  have  ]>rodnced  important  ehauffes  in  the  minor  features  of  the  surface 

)f   the  continent.      .Many   of   these    ponds,  after   heeoming   ehoke(l   with 

iref,'etation   and   conveited    into   peat   swamps,   have   been    drained    and 

furnish  rich  garden-lands. 

Where    brooks    and    ereeks    How    tlm     .;h    forested    regions,    it    fre- 
quently happens  that  large  trees  fall  a(  r(».ss  them  and  retain  the  sticks 
id  leaves  swept  along  by  the  current.     When  sueh  a  start  is  nu  de,  the 
uid  carrittd,  especially  during  freshets,  is  lodged  among  the  leaves  and 
ranches,  and  tends  still  farther  to  obstiuct  the  drainage  and  lead  to  the 
Munition  of  swamps  and  lakes.     This  process  has  been  obseived  espe- 
lj)lly  in  Red  river,  Louisiana,  where  timber  rafts  several  square  miles  in 
3a,  and  covered  with  living  vegetation,  form  floating  islands  and  dam 
^e  streams  so  as  to  cause  their  waters  to  si)read  out  in  shallow  lakes 
irenty  to  thirty  miles  in  length.* 

Numerous  instances  in  the  Yukon  river,  in  Alaska,  were  observed  by 
|e  writer,  where  lateral  branches  of  the  stream  and  the  passage  ways 
Itween  islands,  were  closed  by  accumulations  of  drift  logs  that  greatly 
strueted  the  flow  of  the  watei-s.    In  some  instances  these  acjumnlations, 
olllcd  "  wood  yards  "  l)y  steamboat  men,  are  several  acres  in  extent. 

Still  another  way  in  which  oiganie  agencies  lead  to  the  foiination  of 
bteins  may  be  ob-served  in  swamps  where  vegetable  matter  buried  beneath 
nWJ'l  iind  clay  is  undergoing  decomposition.  Openings  similar  to  those 
produced  in  alluvial  dejxtsits  by  the  violent  escajje  of  water  during  earth- 
q^kes,  but  not  necessarily  connected  with  such  disturbances,  are  formed 
iil;:^narshes  by  the  violent  esca])e  of  gases  from  below.     Instances  of  this 

oeeurrence  have  come  under  the  writer's  notice  on  Smoke  Creek  desert, 

■  ^. 

,Z}  Charles  Lyell.  "  Principles  of  Geol()<,'y."  11th  ed.,  Vol.  1,  p.  441.  Iluinplirey.s  &  Abbott, 
ort  oil  the  Physics  and  Hydraulics  of  the  Mississippi,"  Professional  Papers,  Corps  of 
eers,  U.  S.  A.,  1801.  p.  S7. 


I'jlTf* 

a^ 

^^ 

28 

LAKKS    OK    NOltril    AMKIMCA. 

Novada,  and 

«>Il    s\v 

unpv  uvas   lu'ar  Suiitliisky,  Ohio. 

Wht-n 

tlu'sc 

,ljas 

t'ruptioiis  oi'i".'.!',  till'  soft  luud  is  soiiu'liiiu's  throw  ii  to  a  tlistaiicc  of  oiic  or 
two  Imiidivtl  fcot,  ainu'oiMi'al  dopri'ssioiis  ari'  foiim-d  wliicli  in  soiin'  of  tli 
iiistaiU't's  ohsiTvi'd,  art'  twoiily  fi't't   or  moic  in  iu'|>tli.     Tl 


u'  i-aviiii;'  111  o 


tlu'  l)anks'  lioh's  sonu'timt's  h-ads  to  tlu'  foniiatioii  of  pools  lifty  or  sixt 
fi'i't  ill  dianu'tfr.  llu'  riirular  poiuls  fii'i[iii'iitly  to  lu'  si'i'ii  in  s\vaiii|) 
n>i^ions,    wlii'ii    not    diii'    to    riu'roafliinjjf   vi'iji'talioii,    probably,    in    iis:iii 


instaiu'i's,  on_L;iiia 


ti'.l 


111  liii'  inaniii'r  iifif  noted 


.11 


'I'l'.t'  n'l'ncration  of  Ljascs,  iirinripally  iMihnri'li'd  liydroL^cn.  in  tlif  s( 
mud  of  till'  Mississippi  tU'lta,  lansi-s  ch'vations  known  as  "  mud  liiiiips.  ' 
■wliirli  in  sonii'  instaui'i's  ari^  Iwt'Uty-livf  feet  lii>;h.  Iiit'ijualitii's  pro 
duri'd  in  tliis  maniu'r  miijlit  rasily  lead  to  the  obstriution  of  draiuai;i' 
and  till'  formatioK  of  laki's,  hut  no  instance  of  surli  an  ofi'iirivui'i'  soi'ni-< 


toh 


lavo  hi'i'u  ri'poi 


ti'd. 


IM 


It  lias  fivqufutly  hi-fu  ohsorvfil  tluil  cittlr  on  visiting;  swampy  plai^ 
carry  away  i-onsidi'riihlo  iniantitii's  of   mud,  Millu'iiii!:;-   to   tlu'ir   h't't    a 
matti'd  ii;  tlu'ir  hair,     in  arid  conntrii's  wlit'ii'  diinkint;'  placi's  vav  usually 
ill  and  wiiU'lv  si-atti'i'i'd,  tlu'v  ari'  visited  hv  liitth'  iind  otlu'r  animals  in 


(tin 


larLji'  nuiulu'is  und  a  marked  onlaroiMU'nt  of  tlic  water  lioli's  is  prodnrc 


in   till'    nianui'r   just    stalfd 


Tl 


lis    proci'ss    was    mori'    important     wluii 


thi'  plains  of  North   Anu'rira  wi'ii'  dt'iisi'ly   inhahiti'd  hy   hisoui- 


M; 


inv 

pcri'unial  [lools  and  still  nioit'  nnmi'rons  di'pri'ssious  that  an'  wati'r-tilliil 
ojily  durinjjf  rainy  seasons,  air  k-iown  as  "  hulValo-wallows,"  and  ;ii\ 
b»>lii'\rd  to  owe  thi'ir  orii;in  to  a  <;ri'at  I'xti'iit  to  thf  earryiiiij  away  ol 
mud  I'litanu'lid  iu  the  thiek  hair  of  the  animals  nfter  whieh  they  iiiv 
named. 


In    the    Appah.iehians   there   are   several    water  holes,  usually  on    tl 


'rests  of   ridties,   that    are   ealled  "hear-wallt 


)WS, 


md   are   said   to   h; 


n  1 


been   formed   by  beaix  that  sonn'ht   m»)ist   plaees  in  whieh  to  eool  tlie.ii 


Helves   'Uiruig   lint  we 
habit. 


lit! 


lor. 


IS    is  wi 


11   1. 


viiown,  sw 


ine   1 


lave   a  siimkir 


HnNlns  <luo  to  iiKtvoiiuMits  In  tlio  «*s^rtir,s  enist.  —  Hreat  elian<j;es  iiii 
the  earth's  erust  have  prodneed  eontinenis  and  oeeii'i-basins,  while  smalliij 
movements  on  land  areas  have  resulted  in  the  formation  of  inouiitains  ami 
valleys.  l>urin«;'  the  jfrowth  of  mountains  it  sometimes  hap(tens  that  tluj 
rejjfioii  iH'tween  difVen'ut  systems  or  between  two  or  more  ranj^es,  beeonnv 
eni  losed  so  as  to  form  a  basin.  This  proiiess  has  Ikhmi  in  aetion  in  varieii- 
loealities  siiiee  hind  first  up(>eared.  and  durinjj;  the  eoursi*  of  ijeohioieal  eiu<| 


OUKUN    OF    1,AKK    UASINS. 


tht>s(>    Ljiis 

dl'  Diu'  or 

)UU'  t>t    till' 

tvini;'  ill  "t 
ty  or  sixtv 
11  s\viimii\ 
,    in    iii;ui\ 

in  till'  soft 
ul  lumps.' 
iilitios  pro- 
)t"  ilniina^r 

VIU'C  SOlMlls 

impy  pliUHs 
ir    I'l'i't    ;ini 
i.io  usually 
r  aiiiumls  in 
is  pnuluind 
rtaut    wlu'u 
us.      Maii\ 
wattM'-tiUttl 
iiiul    arc 
ins;'  away  ol 
•h    lliry   arc 

tally  »>n   tl'l 
uiil    to   lia\c 
vo()l    tin. Ill 
•(>   ;i  simihii'l 


rhauijcs  ml 
hilo  smallcij 
.)uutait\s  anil| 
H'us  that  tl 

.•OS,  luH'tUlll'^ 

)ti  iu  vanoi^i 


must  liavo  tt'sulti'd  in  tlu>  loiiuatioii  of  luaiiy  lakes;  hit'  cxainplos  of  wutor 
Iiodii's  of  this  typ(>  aiv  laiv  at  the  pfesont  tiiiit'.  ptiini|).illy  l"(U'  the  ivasou 
iliat  the  (It'i'oiiitatioii  o{  the  earth's  ciust  ttsiially  y-oes  on  slowly  ittttl  the 
(leptesslotis  fotiued  ate  ihaiiinl  »tr  lilleil  with  se(limt'iil.>>  its  rapidly  as 
they  are  formed. 

IMie  liest  I'xamples  on  this  et)tititient  of  hasitis  fortned  hy  the  upheaval 
of  moiuKains  around  tlu-ni,  oecitr  in  the  L;'reat  area  of  interior  (lraiuay;o 
hetweeii  the  Koeky  iiKUintains  and  the  Sierra  Nevada.  The  majority  of 
till'  minor  hasius  in  this  reyioii,  however,  ari-  diu>  to  .seet)ndaiy  tause.s, 
hut  the  vast  seas,  sneli  as  lakes  noiuteville  and  Lahoutan,  wliieli  h>r- 
merly  existed  there,  (u  cupit'il  hasius  of  the  ehaiaeter  here  referred  to. 

'riu>  Latireutian  hikes  are  ludd  in  hasius  produt'ed  in  part  hy  i-rustal 
iiiovemeiils  alVeitiun'  lai'oe  ait'as,  and  in  part  hy  eoiulilions  ri'suliino-  from 
other  causes.  l>asins  art'  also  produced  \)\  less  extensive  elevations  and 
depressions  of  the  earth's  i-rusi.  The  corrupttion  of  a  rcLjiou,  o\\  iu^;'  to 
I  m  the  hirmation  of  a  scries  of  approxim;itely  parallel  folds,  known  as  anti- 
cliiials  and  syiu'liuals,  as  iu  the  ease  of  the  Appalachian  mountains,  must 
fretpieutly  produce  hasius  in  which  water  wouhl  he  ri'lained,  were  the 
process  allowed  to  yt)  on  witlnmt  some  eouute-ai'tiui^'  ai;ency  ;  hut  hero 
auain,  the  movemeuts  are  usually  so  slow  that,  es]tecially  in  hniuid  regions, 
till'  depressions  produci'd  are  destroyod  as  rapidly  as  they  are  formed. 
While  lakes  iu  syiu'liual  hasius  luiohi  he  ex|ii'cted  to  hv  of  common  occur- 
rence, they  are  in  reality  si>  rare  that,  so  far  a..  1  aiu  aware,  none  of  the 
tens  of  thousands  of  the  lakes  of  America  can  ho  pointed  to  as  examples. 
'I'hero  is  still  another  variety  of  earth  inoveiiu'uts  iu  many  instances 
less  oiadual  than  thi>se  referred  ti»  ahove,  to  which  utauy  lakes  owe  their 
ori^'in. 

Fraetures  in  the  earth's  crust  oi-cur  in   disturhed   rejifions  and  may  he 

scores  or  even   hundreds  of   mih's   in   Iciiotli.     'I'ho  edsfcs  of  the   hrokeii 

I  strata  on  one  side  of  a   fracture  are  somi'times  elevated,  or  those  on   the 

opposite  sitle  depressed,  thus  torminn'  what   is  known  as  a  "  fault."     'I'ho 

U>'rowth  of  faults  som»'(inies  i^oes  on  so  slowly  that  no  pronounced  chaujjes 

in   to|)ooiaphy  result,  for  the  reason  that   the  rocks  on   the  upheaved  side 

[of  tlu'   fracture   are  eroded  away  as    fast   as   they  are   raised.      .\t   other 

Itimes.  however,  uiouutain   rani>i's  are    [H'oduood,  in   whiih    the  strata  are 

linclin.  (i  av, ay  from  the  steep,  hrokeu  face  overlookiiij^;  the  lino  of  fracture. 

Ilii  reL;ioU8  where  sui-h  mountain  ranees  have  hceii  formed  with  comjnuativo 

|rapidity  and  where  deiunlinjx  aijeneies  are  weak,  yreat  disturUuiees  in  tlio 

Irainaufo  result,  and  "fault   hasius"  are  common.     Nuiuorous  husins  of 


■w^ 


80 


LAKES    OF    NOKTH    AMP:KICA. 


this  character  occur  in  the  Arid  region  and  especially  in  Nevada  ami 
sontheastern  California,  but  probably  the  most  typical  example  is  the 
one  occupied  by  Abert  lake,  Oregon. 

Along  the  east  side  of  Abert  lake  there  is  a  long  line  of  magnificent 
piilisades,  several  hundred  feet  high,  formed  by  the  precipitous  face  of  an 
eastward  dipping  fault  Ijlock  ;  the  lake  washes  the  base  of  this  escape- 
ment and  occupies  the  depression  formed  by  the  subsidence  of  the  rocks 
on  the  west  side  f)f  the  fracture.  Sinnething  of  the  appearance  of  Abert 
lake,  as  seen  from  the  crest  of  the  palisades  a  few  miles  to  south  of  its 
southern  end,  and  also  of  the  general  structure  of  the  iniderlying  rocks, 
may  be  gathered  from  the  accompanying  illustration.  The  lake  is  about 
fifteen  miles  long  with  an  average  width  of  nearly  four  miles,  and  is 
shallow.  It  receives  the  water  of  a  single  creek,  but  does  not  overflow 
and  is  intensely  alkaline. 

Many  of  the  lakes  of  the  ^Vrid  region  are  of  the  Abert  type,  but 
usually  the  great  depressions  in  which  they  occur  have  become  deeply 
filled  with  the  sediments  of  older  water  bodies,  and  they  may  be  considered 
as  occupying  depressions  on  ne\v  land  areas,  or  as  belonging  to  the  class 
of  basins  here  consulered,  as  one  prefers. 

In  some  instances  the  faulting  that  gave  origin  to  the  characteristic 
topography  of  the  Great  Basin  region  has  been  continued  to  the  present 
time,  and  produced  escarpments  across  the  bottoms  of  the  deeply  tilk'd 
valleys,  so  that  the  existing  water-bodies  are  confined  in  jiart  by  recent 
fault  scari)S.  An  instance  of  this  nature  is  furnished  by  Mono  lake,  Cali-! 
fornia,  which  washes  the  base  of  a  precipice  formed  by  a  recent  movement  I 
of  the  great  Siena  Nevada  fault.  A  similar  association  has  also  been 
observed  in  coinieetion  with  several  of  the  lakes  of  western  Nevada. 

When  a  fault  crosses  the  course  of  a  river,  the  edge  of  the  upturned 
block  may  rise  so  slowly  that  the  stream  is  able  to  maintain  its  course  j 
and  cut  a  channel  through  the  obstruction  as  it  is  elevated,  and  a  lake  isj 
not  formed.     Numerous  instances  of  this  nature  have  been  observed  by 
the  writer  in  the  central  part  of  the  state  of  Washington,  where  tlu'| 
Columbia  and  the  Yackima  river  have  eroded  deep  narrow  gorges  tlirou<(li  M 
the  edges  of  fault  blocks  that  were  upheaved  across  their  courses. 

With  basins  produced  by  faulting,  as  in  other  instances  of  surfiut| 
ine(|ualities  due  to  movements  of  the  earth's  crust,  the  question  whether 
lake  vvill  be  formed  or  not,  is  ansA\x>red  mainly  by  the  climatic  conditio! in  2 
In  aril  regions  the  surface  effects  of  orographic  movements  are  countii- 
acted  by  erosion  but  slowly;  while  in  countries  with  abundant  drain;e4' 


ORIGIN    OF   LAKE   BASINS. 


M 


degradation  goes  on  energetically,  and  nnless  the  deformation  of  tl.e 
surface  is  coni[)aratively  rapid,  no  pronounced  topograj)hic  changes  result. 
It  is  the  '-atio  between  the  rate  of  deformation  and  denudation  which  de- 
termines whether  basins  shall  be  formed  or  not.  Evidently  tlie  most  favor- 
able regions  for  studying  the  effects  of  movements  in  the  eartli's  crust  on 
tlie  surface  relief,  are  those  in  which  the  meteoric  and  aqueous,  agencies 
are  least  energetic,  namely,  in  arid  regions. 

Basins  due  to  Innd-slldoH.  —  On  steep  slopes  great  masses  of  rocks 
and  earth  not  infre»iuently  break  away,  especially  after  heavy  rains,  and 
descend  su(hlenly  as  hind-slides  into  the  adjacent  valley.  .When  this 
occurs,  the  drainage  in  the  valley  may  be  obstructed  so  as  to  ca\ise  lakes 
to  form.  Avalanches  of  snow  and  loose  rocks  also  produce  similar  results, 
but  of  a  less  pronounced  character. 

Small  lakes  originate  in  many  cases  on  the  surface  of  land-slides 
owing  to  the  fact  that  such  surfaces,  after  the  descending  mass  has  come 
to  rest,  usually  incline  toward  the  clitfs  from  which  they  l)roke  away,  in 
such  a  manner  as  to  enclose  ])asins.  At  times,  a  lanil-slidc  plows  up  the 
tioor  of  the  valley  into  whieh  it  })lunges  and  forms  a  ridge,  not  unlike  a 
terminal  moraine,  Avhicli  may  also  act  as  a  dam  and  hold  a  lake  in  check. . 
Examples  of  l)asins  formed  in  each  of  tliese  several  ways  have  been 
examined  by  the  Avriter  in  the  state  of  Washington  ^  and  in  other  regions, 
but  need  not  be  described  at  this  time. 

JBnsins  due  to  chemical  action.  —  In  limestone  countries  the  <1  inage 
is  often  subterranean  and  finds  its  way  through  caverns  formed  by  the 
solution  of  the  rock.  The  roofs  of  such  caverns  fall  in  as  the  general 
erosion  of  the  region  progresses,  and  obstruct  the  drainage  channels  so  as 
to  form  lakes.  The  surface  waters  reach  imderground  channels  througli 
openings  termed  "  sink-lioles,"  or  "swallow-lioles,"  which  are  enlarged  by 
solution,  and  frequently  become  closed  so  as  to  hold  pon(h:.  In  portions 
of  Kentucky  and  througliout  the  (ireat  A^jpalachian  valley,  where  the 
underlying  rock  is  limestone,  circuhir  jjonds  of  this  nature  are  so  numer- 
ous that  they  give  character  to  the  landscajje.  Lakes  also  occur  in  the 
caverns  themselves,  owing  to  various  causes,  the  most  fre([uent  I;eing  the 

;  falling  of  portions  of  their  stalactic  roofs,  as  may  be  seen  in  Mammoth 

jftnd  Luray  caverns. 

'  "Geological  Uecnmidissancc  in  Central  Wasliiiigtnii,"  U.  S.  Gcol.  Siirv.,  Bulletin  No.  I.18. 


H 

82 

LAKES    OF 

Basins  of  small  size,  due  to  chemical  precipitation,  occur  in  connection 
with  sj^rings  that  deposit  calcareous  tufa  or  siliceous  cinter.  Many  ex- 
am])les  of  pools  formed  in  tliis  way  occur  in  the  Yellowstone  National 
Park  and  in  other  hot  s])ring  regions  of  the  Cordilleras.  Near  the  Avesi 
shore  of  Mono  laite,  California,  there  is  a  castle-like  bowl  of  calcareous 
tufa^  fully  50  feet  liigh  and  from  loO  to  200  feet  in  diameter,  Avith  several 
long  aqueduct-like  branches,  which  was  formed  from  the  water  of  a  sprini; 
that  has  now  ceased  to  flow.  Far  out  on  the  desert  valleys  of  Utah  and 
^  vada  one  sometimes  finds  circular  basins  with  rims  of  tufa  from  a  few 
inches  to  three  or  four  feet  high,  and  holding  beautifully  clear  water  with 
a  temperature  approaching  the  boiling  point.  In  othei  instances,  thesr 
deposits  rise  several  feet  above  the  adjacent  surface  and  resemble  volcanii 
craters.     In  their  sununits  there  are  frequently  steaming  caldrons. 

In  regions  underlain  by  gypsum,  rock  salt,  and  other  easily  solul)lr 
substances,  depressions  are  formed  on  account  of  the  removal  in  solution 
of  the  rocks  beneatli  and  the  subsidence  of  the  surface. 

Gypsum  is  thought  by  some  geologists  to  owe  its  formation  to  the 
alteration  of  limestone  by  the  passage  through  it  of  sulpluirous  gases  or 
of  sul2)hurous  Avaters.     When  this  occurs,  the  volume  of  the  deposit  is   , 
increased  and  the  ground  above  may  be  elevated  into  mounds,  and  thu« 
obstruct  the  drainage. 

CONCLUSION. 

In  this  chapter  an  attempt  has  been   made  to  describe  briefly  the 
principal  types  of  lake  basins  occurring  in  North  America,  to  indicate  the 
processes  by  which  they  have  been  formed,  and  to  sho\r  to  some  extent,  1 
where  they  severally  belong  in  the  history  of  topographical  development. 

Many  basins  have  resulted  from  the  action  of  more  than  one  agency,  i 
and  in  not  a  few  instances  several  agencies  have  coiiperated  in  their  h 
production.  Basins  of  a  composite  character  have  thus  originated,  butj 
the  principal  cause  leading  to  their  existence  is  usually  so  pronounced 
that  when  carefully  studied,  they  may  without  great  violence  be  referred 
to  some  one  of  the  types  here  described. 

The  study  of  lakes  has  shown  that  they  frequently  have  a  long  and  <! 
varied  history,  which  is  no  less  interesting  and  instructive  than  the  stoiva 
of  the  origin  and  decadence  of  the  hills  that  are  reflected  in  their  glassy | 
depths.  Some  of  the  phases  of  their  not  uneventful  lives  are  described? 
in  the  succeeding  chapters. 


'1 

■jS, 


I  ! 


onnection 
Many  ex- 
1  Natioiiiil 
r  the  west 
cakaieous 
itli  several 
:)f  a  sprinji' 
Utah  antl 
from  a  few 
water  with 
,iice.s,  these 
)le  volcanic 
ons. 

sily  solnhlc 
in  solution 

,tion  to  the 
[)us  gases  or 
B  deposit  is 
lis,  and  thus 


briefly  the 
indicate  the 
iome  extent, 
evelopment. 
one  agency, 
ted  in  their 
ixinated,  butj 
pronounceil 
be  referred 

a  long  and' 
lan  the  ston ; 

their  gla>syj 
ire  described 


CHAPTER   II. 

MOVEMENTS    OP     LAKE    WATERS    AND    THE    GEOLOGICAL 

FUNCTIONS  OP   LAKES. 

Tides.  —  The  waters  of  lakes  are  influenced  by  the  attraction  of  the 
sun  and  moon  in  the  same  manner  as  the  waters  of  tlie  ocean.  Giving 
to  the  comparatively  small  extent  of  inland  water-bodies,  however,  the 
rise  of  their  waters  is  so  small  that  it  is  not  noticeable,  and  can  only  be 
determined  by  refined  measurements. 

Observations  made  by  the  U.  S.  Lake  Survey  at  Chicago,  have  shown 
that  Lake  Michigan  has  a  tide  with  an  amplitude  of  1^  inches  for  the 
neap  tide  and  3  inches  for  the  s|)ring  tide. 

"Waves  ami  eurronts.  —  Tlie  waters  of  fresh  lakes  respond  to  tlie 
influences  of  the  wind  more  (piickly  than  the  heavier  waters  of  the  ocean, 
but  the  waves  produced  are  smaller  and  less  regular  than  in  the  open  sea. 
On  the  Laurentian  lakes,  waves  from  15  to  18  feet  in  amplitude  have 
been  observed  during  long  continued  storms.  The  heavy  ground  swell 
of  the  ocean  is  but  faintly  reproduced  by  the  fresh  water  "seas."  During 
rough  weather  on  tlie  lakes  the  waves  are  more  like  the  short,  "cho]) 
seas  "  than  the  heavy  surges  of  tlie  open  ocean. 

The  friction  of  the  wind  on  the  surfaces  of  lakes  ])roduces  very  decided 
movements  in  their  waters.  In  their  central  portions,  especially,  there  are 
frequently  strong  currents  due  to  this  cause,  in  addition  to  the  slow 
movement  of  the  waters  toward  an  outlet.  A  study  of  the  currents  of 
the  Laurentian  lakes  has  been  undertaken  by  the  United  States  Weather 
liureau,  by  means  of  bottles  containing  a  record  of  the  locality  where 
tlicy  were  set  adrift  and  a  request  that  the  finder  will  note  the  locality 
where  they  are  recovered  ami  transmit  the  record  to  the  Chief  of  the 
Weather  Bureau.  The  results  of  observations  made  in  the  sunnner  season 
of  1892  and  1893,  have  been  published,^  and  the  general  coui-ses  of  the 
:  currents  so  far  as  ascertained,  indicated  on  a  chart  which  is  reproduced 
on  Plate  7.  The  eft'ects  of  the  prevailing  westerly  winds  on  the  surface 
movement  of  certain  of  the  Laurentian  lakes,  is  indicated  by  the  trend 

1  U.  S.  Department  of  Agriculture,  Weather  Bureau,  llulletin  B. 


fW^ 


34 


LAKES   OF    NORTH    AMEKICA. 


iiiliiiil 


lll;i!K 


'■'\m: 


of  the  principal  curreuts.  When  the  hirger  axis  of  a  lake  coincides  with 
the  direction  of  the  prevailing  winds,  a  surface  current  is  established 
thiough  its  center,  as  in  the  case  of  lakes  Erie  and  Ontario,  with  return 
currents  and  eddies  along  the  shore  and  about  islands.  When  lakes  lie 
athwart  tlie  prevailing  winds  the  main  currents  combine  with  the  return 
currents  and  form  minor  swirls,  as  is  shown  on  the  chart  in  the  case 
of  lakes  Micliigan  and  Huron.  In  Lake  Superior  there  is  a  general 
circulation  which  follows  the  main  shore  lines,  but  its  couree  has  not  been 
fully  deterniined.  It  has  been  found  that  the  currents  of  the  Laurentian 
lakes  have  in  general  a  speed  of  from  4  to  12  miles  a  day,  but  in  certain 
observed  instances,  this  is  increased  to  2i-  to  4  miles  an  hour  or  from  8(! 
to  9tt  miles  a  day. 

The  cujreuts  in  the  central  i)art  of  a  lake  produce  slight  if  any 
changes  on  the  topography  of  its  basin,  but  when  they  follow  the  short' 
important  results  may  follow.  When  the  wind  blows  obliquely  to  tht; 
shore,  strong  currents  are  frequently  produced  which  follow  the  general 
trend  of  the  coast,  but  cut  across  bays  and  inlets.  These  currents,  with 
the  assistance  of  waves,  sweep  along  sand  and  gravel,  and  produce  im])or- 
tant  changes  on  the  bottom,  particularly  when  the  water  is  shallow.  Tlie 
role  played  by  waves  and  currents  in  modifying  topography  is  considered 
with  some  detail  in  the  next  succeeding  chapter. 

Strong  winds  blowing  in  a  nearly  uniform  direction  for  several  dfi^-s 
cause  the  waters  of  lakes  to  move  with  them,  and  to  rise  on  the  shores 
against  which  they  are  driven,  so  as  frequently  to  produce  disastrous 
inundations.  A  gale  blowing  from  the  north  over  Lake  Michigan  has 
been  observed  to  cause  a  rise  of  seven  feet  at  Chicago.  Li  Novem- 
ber, 1892,  a  storm  from  the  west  caused  the  waters  of  Lake  F^vW, 
near  Toledo,  to  fall  between  eight  and  nine  feet  below  the  normal  fair  % 
weatlier  level.  At  the  same  time,  unusually  high  water  was  experienced 
at  the  east  end  of  the  lake.  The  differences  in  the  level  of  the  waters  of 
Lake  Erie,  at  liuffalo,  between  a  high-water  stage  produced  by  an  east- 
ward blowing  gale,  and  a  low- water  stage  accompanying  a  westward  or 
off-shore  gale,  has  been  observed  to  amount  to  15i^  feet.  An  eastward 
movement  of  the  waters  of  Lake  Superior  has  been  known  to  accom- 
pany a  gale  from  the  west  and  to  produce  an  unusual  rise  in  the  watrr  S 
of  St.  Mary's  river. 

The  height  to  which  the  waters  reach  on  hike  shores,  owing  to  stroiii: 
winds,  establishes  the  upper  limit  of  wave-action,  and  leads  to  the  forma- 
tion of  storm  beaches  at  an  elevation  of  several  feet  above  the  normal 


ii'* 


ides  with 
itablislit-'il 
ith  return 

lakes  lie 
he  return 

the  case 
a  general 
3  not  been 
jaurentian 

in  certain 
)r  from  BU 

rht  if  any 
V  the  shore 
lely  to  the 
;he  general 
•rents,  with 
luce  impor- 
,llow.  The 
considered 

everal  days 
the  shores 
disastrous 
ichigau  has 
In  Novem- 
Lake    Erie 
normal  fair 
experienced 
le  waters  (»f 
by  an  east-  = 
westward  ov 
Vn  eastwanl 
u  to  accoin- 
iii  the  water 

iicT  to  stroiii,' 
to  the  forniii- 
L>  the  norm;il 


CO 


CO 


en 


LU 


en 


cc 
o 


lii 


1 1         mv  wji 


HI 


iii 


bitir 


ii'Ji 


I 


IP,  ill  I,   II 


I    <i 


liMi,   i. 


con 

lak 

hea 

sioi 

doe 

roe] 

hea 

tint 

low 

uniJ 

win 

lake 

tion 

of   t 

1 
Oct., 

MOVKMKNTS    or    hAKK    WATERS. 


35 


stage.  Wlicn  the  shores  of  ii  hike  are  h)w,  broad  areas  are  imuidaled 
during  storms  that  sweep  tlie  watei-s  towards  them.  New  outlets  may 
be  establislied  at  such  times  across  hiw  divides,  and  lead  to  im[)ortant 
changes  in  drainagei 


Ht'lclio. —  I^akc!  waters  are  also  sensitive  to  changes  in  atmositheric 
I)ressure.  In  some  instances  variations  of  level  during  calm  weather, 
amounting  to  several  feet,  have  been  observed,  and  are  supposed  to  l)e  duo 
to  sudden  changes  in  barometric  pressure  on  dilTerent  portions  of  the 
water  surface.  Besides  these  larger  movements,  which  can  be  coi-ndated 
with  atmospheric  changes,  and  are  known  as  itcirlwx,^  there  are  certain 
rhythmical  pulsations  producing  a  difference  of  level  of  as  much  as  four 
or  live  inches  during  calms,  when  no  variation  in  atmospheric  jjressure  of 
an  analogous  character  can  be  detected.  These  minor  movements  are 
not  thoroughly  luiderstood. 

These  and  other  changes  of  a  similar  nature  are  of  great  interest  in 
connection  with  meteorological  studies,  but  have  little  if  any  geological 
significance. 

It  is  to  be  expected  that  eartlupiakes  would  pniduce  "  tidal  Avaves  "  in 
lakes  similar  to  those  occurring  in  the  ocean,  but  observations  in  this 
i    coraiectiou  are  wanting. 

Toinporaturt'.  —  Lake  waters  are  warmed  by  the  sun's  rays  and  by 
contact  with  the  air.     It  has  also  been  thought  by  some  that  very  deej) 
lakes  ma}'  have  their  bottom  temperatures  moditied  by  the  general  internal 
heat  of  the  earth,  but  observations  do  not  seem  to  sxipport  this  conclu- 
sion.    Water  is  a  poor  radiator  and  an  indifferent  conductor  of  heat,  and 
f  does  not  respond  to  atmospheric  changes  of  temperature  as  quickly  as  do 
rock  surfaces.     Shallow  lakes  are  warmed  throughout  b}'^  the  summer's 
heat  and  chilled  to  the  bottom  by  the  winter's  cold  ;  but  their  tempera- 
ture is  much  more  uniform  than  that  of  the  adjacent  air.     The  shal- 
low lakes  of   the   Noriiiern  states   have    been    fouiul  J;o  have  a  nearly 
uniform  temperature  during  the  summer  months  of  7;")°  Fahrenheit.     In 
•winter  their  temperature  in  general  is,  of  course,  32°  Fahrenheit.     In 
[lakes  having  a  depth  in  excess  of  about  800  feet,  more  interesting  condi- 
;  tions  are  found.    The  temperatures  of  deep  lakes  are  ascertained  by  means 
iof   self-registering   thermometers    attached   to   sounding  lines.      In  this 


*  E.  A.  T7erkins. 
lOct.,  189.3. 


The  Seiche  in  American  Lakes,"  American  Meteorological  Jour., 


<'«*■ 


3(5 


LAKES    OF    NOKTII    AMEUICA. 


way  accurate  measurenu'uta  of  tcmpt'iature  at  various  depths  have  lieen 
luiuie  in  a  uuiuIkt  of  lakes,  hotli  in  America  and  in  Kurope,  with  reniark- 
ahly  consistent  results.  Of  the  observations  thus  far  made  in  this  countiy, 
the  most  instructive  are  by  Professor  .lolni  Le  C'onte,i  in  Lake  Tahoe, 
California.      From  the  report  of  these  observations  1  (piote  the  following  : 

"Tliese  expei'iiiicnts  wcR'  executed  between  tlie  lltli  and  iMtli  oi"  August,  187U. 
Tlie  same  general  icsiill.s  were  olitaiiied  in  all  parts  of  (lie  lake.  Tiie  followiiiu;  table 
contains  an  aiislract  ol  the  uveia^e  residts,  alter  correcting  tlie  thernioiae'.ic  indicatiouH 
by  couiiiarisoii  witli  a  standard  tliernionieter : 


TEMPEBATinE. 

Ollrt. 

Dki'tm  IX  Ki:kt. 

Dei'th  in  Mkikiis. 

Fuhreiiheit  Scale. 

Ceiiti({i'iMl«  Scale. 

1 

0  —  Surface. 

0  =  Surface. 

(J7° 

10.14° 

•  ) 

")(» 

1.-).L'4 

0:3° 

17.22° 

;i 

100 

;5U.4.S 

55° 

12.78° 

4 

irx) 

■l.-).7-J 

50° 

10° 

') 

LIOO 

(iO.Oti 

48° 

8.80° 

(i 

•J.")0 

7(i.-J0 

47° 

■-  8.:}8° 

7 

;!oi) 

01.44 

40° 

.   7.78° 

8 

;5:J0  (Hottoni) 

lOO.oS 

45.5° 

7.50° 

U 

400 

rji.oi' 

45° 

7.72° 

10 

4S0  (Hottoni) 

i4(i.;jo 

44.5° 

0.04° 

11 

TjOO 

152.40 

44°            V 

6.07° 

1-i 

000 

182.88 

4.5° 

6.11° 

1:5 

772  (liottoin) 

2;5.j.:}0 

41°    . 

5° 

14 

1. ")((()  (l5ottoni) 

4')!l.02 

:]!».2° 

4° 

1 

"It  will  be  seen  from  the  foregoins,'  uumber.s  that  the  temperature  of  the  water 
decreases  with  increasing  depth  to  about  700  or  800  feet  (213  or  244  meters),  and 
l)elow  this  depth  it  remains  sensibly  the  same  down  to  1.500  feet  (4.50  meters).  Thi^ 
constant  temjierature  which  jirevails  at  all  depths  below  say  2.')0  meters  is  about 
4°  C.  (:}0.2°  Fahr.).  This  is  precisely  what  niijiht  hav(^  been  expected;  for  it  is  a 
well-established  physical  ]ir()perty  of  fresh  water,  that  it  attains  its  maximum  density  at 
tlu!  above-indicateil  teniju'rature.  In  other  words,  a  mass  of  fresh  water  at  the  tempera- 
ture of  4°  C.  has  a  j^reater  weight  under  a  given  volume  (that  is,  a  cubic  inch  unit 
of  it  is  heavier  at  this  temperature)  than  it  is  at  any  temiterature  either  liigher  nr 
lower.  Hence,  Avhen  tlie  ice-cold  water  of  the  snow-fed  streams  of  s])ring  and  summer 
readies  the  lake,  it  naturally  tends  to  sink  as  soon  as  its  temperature  risi\s  to  4°  C. ; 
and,  converselj^  when  winter  sets  in,  as  soon  as  the  summer-heated  surface-water  is 

1"  Physical  Studies  of  Lake  Tahoe,"  Overland  Monthly,  2d  Series,  vol.  2,  1883,  pp. 
600-510,  595-012 ;  vol.  3,  1804,  pp.  41-40. 


MOVKMKNTS    OF    LAKK    WATKKS. 


87 


,ve  l)een 
remark- 
country, 
3  Tahoe, 
llowing  : 

iiiilications 


■iiili'  Scale. 

7.-'--'° 

>-->.7S° 

7.78° 
7.0(1° 
7.7-J° 
li.!l4° 
l).(i7° 

(>.n° 

5° 
40 


)f  the  water 

lu'tevs).  ami 

t<M-s).     This 

■rs   is   ahoii' 

;    for  it  is  ii 

1111  density  iit 

the  temiievM- 

(ic  iueli   unit 

u'l-  hi.nl"'''  '"■ 
and  Muniiniv 

rises  to  -1°  <■'■'• 
if  ace-water  1- 


1.  2,  1883,  rr- 


cooled  to  4°,  it  tendB  to  hIiiK".  Any  further  rise  of  the  teinperalnie  of  the  surface-water 
(luriim  the  warm  season,  or  fall  of  tcniperatine  durini;  the  <'()ld  season,  alike  produces 
expansion,  and  thus  causes  it  to  tioat  on  tiie  iieax  ier  water  lielow  ;  .xo  that  water  at 
t°  C.  i)erj)etually  remains  at  tlie  hottoni,  while  llie  varyini;  temin'rature  of  the  seawnis 
and  the  penetration  of  the  solar  heat  only  inllnen<M'  a  surface  stratum  of  ahont  'J.'tO 
meters  in  thickness.  It  is  evident  that  the  eontinnal  outtlow  of  water  from  its  sliallow 
outlet  cannot  disturh  the  mass  of  liquid  occupyinj;'  the  deeper  portions  ot  the  lake.  It 
tinis  results  that  the  temi^rature  of  the  «urface-.stratum  of  sncii  liodies  of  fresji  water 
for  a  curtain  deptii  fluctuates  with  the  cliniide  and  with  the  seasons  ;  hut  at  the  hottoni 
of  deep  lakes  it  undereoes  little  or  no  clianj;!'  throu,i;hout  the  year,  and  apjiroaches  to 
that  whidi  corresponds  to  tin:  maxinuim  <leMsity  of  fresh  water." 

Iiifliiciico  of  lakos  4»ii  cliiiiatt'. — ^  Inland  wiitor  liodit'.s  exert  an  iniiior- 
tant  iniliiein'e  on  the  clhnatf  of  tlieir  sliorcs.  in  rct'ert'iice  o.s|H'ci;illy  to 
ti'inpcvaturi'  and  liuniidity,  and  also  on  tin-  dirt'cti(»ii  and  cliarai'tcr  of  the 
more  f,'entle  winds.  The  surface  \vater.s  of  lakes  receive  their  temi)erature 
in  a  great  measure  from  t!ie  air  in  contact  with  them,  and  are  warmed  or 
cooled  at  rates  having  some  relation  to  their  depth.  The  tcmjierature  of 
shallow  lakes  varies  but  little  from  that  of  the  adjacent  atmosj)heie,  Imt 
changes  less  rapidly  for  the  reason, already  stated,  that  water  surfaces  are 
poor  radiators.  The  ditt'erences  between  the  rates  of  radiation  between 
adjacent  land  and  water  surfaces,  affect  the  temperature  of  the  air  above 
them,  and  in  calm  weather  give  origin  to  lake  and  land  breezes. 

The  tens  of  thousands  of  small   lakc!s  scattered  over  the  glaciated 

[portions  of  North  America  have  an  important  combined  influence  on  the 

general  climate,  althfiugh  their  effects  may,  perhaps,  be  diHicidt  of  direct 

determination.     These  lakes  cool  and  moisten  the  atmosphere  by  eva|)ora- 

Ition  during  the   hot  sunnner  months,   and  when   they   frei'/.e   as  winter 

[approaches,  a  vast  amount  of  "latent  heat"   is  liberated  and  moderates 

[the  full  in  temperature.     It  is  stated  by  physicists  that  every  ton  of  xyiter 

jconvertc  I  into  ice  gives  out  as  nuich  heat  as  would  be  required  to  raise 

Ithe  same  (luantity  of  water   from  :»0°   to  174'^   Fahreidieit.      A  reverse 

)rocess,  not  so  congenial  to  the  welfare  of  man.  takes  place,  however, 

lien  the  ice  n^dts  in  si)ring,  as  then  an  amount  of  energy  equal  to  that 

)reviously  lost,  must  be  again  absorbed  in  order  that  the  ice  may  change 

jto  water.     The  warm  southern  winds  are  thus  chilled  and  the  opening  of 

|;lic  flowers  delayed. 

Deep  lakes,  as  already  seen,  have  a. uniform  bottom  temperature  of  39 
legrees  of  the  Fahrenheit  scale,  and  do  not  freeze  in  winter  except  about 
fhcir  shores   where  the  water  is  shallow,  for  the   reason   that  the   low 
Jmperature  of  the  air  above  them  does  not  continue  long  enough  for  the 


Il'ppfp 


38 


LAKKH   OK    NOKTH    AMKUICA. 


IK' 


entire  water-body  to  beooine  cooled  to  tlie  depfree  of  maximum  density. 
I'ntil  this  liii|i|tens  the  water  cooled  at  the  surliuc  from  contact  witii  the 
ail',  has  its  density  increast'd  and  sinks,  and  is  leplaced  !)y  warmer  and 
conse([uently  lij^diter  water,  risin<,'  from  l)eh)W,  and  ice  cannot  form. 

Tile  snrfact'  waters  of  i\vv\)  lakes  are  thus  above  the  mean  temperature 
of  the  adjacent  atmosphere  in  winter;  but  in  summer  they  are  cooler  than 
the  air,  as  the  warmed  surface  layer  loses  heat  by  conduction  downward. 
'J'hc  winds  that  i)low  over  them  are  thus  teiii[tered  in  a  manner  congenial 
to  the  urowth  of  vegetation  both  in  warm  and  in  cold  weather. 

The  inlliieiice  of  the  Laureiitian  lakes  on  the  climate  of  their  shores 
is  w(dl  marked,  as  was  clearly  shown  many  years  since  by  Alexander 
Wincladl.'  On  charts  that  have  apjieared  showing  the  winter  and  sum- 
mer is(»bar,  that  is,  lines  drawn  through  the  various  localities  having  the 
same  mean  tem[)erature,  the  lines  showing  the  mean  summer  temi)eiatnre 
curve  northward  in  the  vicinity  of  Lake  Michigan  especially,  while  tlu; 
lines  indicating  mean  winter  temperature  present  an  ecjually  marked 
southern  curvature,  showing  that  the  lakes  cool  the  air  that  [)asses  over 
them  in  summer  and  warm  it  in  winter.  The  genial  intlueiice  of  the 
lakes  is  also  plainly  to  be  seen  in  the  distribution  of  the  fruit-belts  of 
Michigan,  Ohio,  and  New  York. 

If  we  should  construct  a  maj)  showing  the  mean  humidity  of  the  air, 
by  drawing  lines  through  the  loc:  .ties  having  the  same  "relative  humid- 
ity," the  influence  of  the  lakes  would  be  quite  as  ap})arent  as  in  the  case 
of  the  isothermal  lines,  but  the  curvature  in  both  winter  and  summer 
would  be  southward. 

The  amelioration  of  climate  produced  by  large  inland  water-bodies 
has  an  important  influence  on  the  flora  and  fauna  of  their  borders,  and 
therefore  on  the  character  of  the  fossils  entombed  in  their  sediments, 
Another  fact  of  geological  interest  in  this  connection,  is  that  rocks  decay 
more  rapidly  under  warm,  moist  climates  than  in  arid  or  in  Arctic  regions, 
and  deeper  and  richer  soils  are  produced.  This,  again,  influences  the 
life  of  lake  regions,  and  is,  perhaps,  of  sufficient  importance  to  be  con-  | 
sideretl  in  interpreting  the  records  of  ancient  inland  water-bodies. 


iii 


mm 


Influence  of  lakes  on  the  floAV  of  streams. —  Lakes  act  as  8tora|,f(' 
reservoii-s  and  regulate  the  flow  of  the  streams,  of  which  they  are  enlarge-  ^ 
ments.     In  the  case  of  a  river  subject  to  sudden  freshets,  the  disastrous 

i"The  isothcrmals  of  the  Lake  Region,"  Am.  Assoc.  Adv.  Sci.,  Proc,  vol.  10,  Troyj 
Meeting,  1870,  pp.  100-117. 


MOVEMKNTH   (»!"    L\KK    WATKltH. 


89 


IcuHity- 
.itli  thf 
u-v  iiinl 
I. 

(lev  tliitii 
wiiwiivd. 
oiigoiiiiil 

Jexandi'i' 
and  siun- 
iving  tlif 

wliile  tlu! 
y  marked 
lasses  ovt'V 
ICC  of  the 
litrbcUs  of 

of  the  air, 
ive  humid- 
iu  llie  ease 
kI  Hiunmcv 

rater-l)odios 

lorders,  and 
sediments, 
ocks  decay 
tic;  regions, 
uences  tlie 
to  be  con- 
ies. 

t  as  storage 
are  enlarge- 1 
lie  disastrous 

vol.  10,  Troy 


cffcct.s  of  a  Hiiddcii  rise  would  1m'  chcckc(l,  and  even  entirely  averted,  if 
a  lake  of  Hiitliciciit  .size  existtMl  in  its  middle  couixc,  (»r  if  there  were  a 
nnndu'r  of  lakes  on  its  trihutary  streams. 

Tiie  niodnlatinjjf  inlliience  of  lakes  on  tlie  How  of  str«'anis  is  well 
known  to  hydraulic  enjfineei"s:  and  it  has  been  proposed  to  rej,ndate  tiie 
tlow  of  the  .Mississippi  by  building  storaj^e  reservoirs  on  its  head  watt'rs. 
Such  reservoii-s  could  be  lilled  (hu'in<,'  floods  and  tiie  water  allowed  to 
escai»e  when  the  danger  stage  iiad  pa.sscd.  In  this  manner  the  disasters 
resulting  from  annual  freshets  could  be  averted  and  navigation  inijirovcd 
durin<'  the  .seasons  (d'  low  watei'. 

The  effect  of  gales  in  lieaping  up  the  waters  if  lakes  on  the  shores 
against  which  they  bh)W  has  alicady  been  netted,  and  an  instance  cited 
where  the  watei-s  of  St.  Mary's  river  were  suddenly  raised  by  a  gale  on 
Lake  Superior.  A  rise  of  thi'  water  in  streams  flowing  from  large  lakes, 
due  to  this  cause,  is  exeeiitional,  however,  and  li  no  means  as  destructive 
as  the  fluctuations  produced  by  storms  and  melting  snow  on  water  eoui-ses 
that  are  without  the  regulating  inllucm-es  of  large  lakes. 

The  sudden  escape  of  lakes  held  by  dams  of  ice  also  causes  floods  in 
the  streams  below,  as  in  the  c<i.se  already  cited  of  the  Hhoiic.  when  Miir- 
jelen  lake  is  drained,  and  of  the  Stiekeen,  where  the  glacial-held  lakes  on 
its  tributaries  break  their  icy  bands. 

The  rise  of  Lake  Bonneville  until  it  found  an  outlet  and  then  rapidly 

cut  down  its  channel  of  (lischarj.e   through  unconsolidated  material,  as 

will  be  described  in  advance,  is  supposed  to  have  caused  a  great  rise  in 

Snake  river,  to  which  it  became  tributary.     In  these  and  other  ways  that 

[might  be  cited,  it  aiijiears  that  lakes  may  cause  floods  in  their  draiiung 

iBtreams  as  well  as  avert  them. 

Lakes  as  sottliiifr  basiii.s.  —  The  streams  flowing  into  lakes  are  fre- 
quently turbid  and  heavy  with  sediment,  esjiecially  after  storms,  but  the 
livers  flowing  horn  them  are  usually  clear  and  free  from  all  but  po.ssibly 
le  flnest  of  material  in  sus[)ension.  During  the  slow  [)as.sage  of  the 
mters  through  a  lake  which  has  an  outlet,  the  material  in  suspension 
ills  to  the  bottom  and  contributes  to  the  filling  of  the  basin,  while  the 
Clarified  waters  flow  on. 

The  fact  that  Indies  of  standing  water  retain  the  mineral  matter 
bought  to  them  in  suspension,  is  illustrated  more  or  less  i)erfectly  in 
learly  every  lake  and  pond,  and  even  by  ephemeral  pools  by  tlie  wayside, 
it  is  especially  marked  in  great  seas  like  those  drained  by  the  St.  Law- 


m 


40 


LAKES   OF   NORTH   AMERICA'. 


rence.  Durinjr  storms,  all  of  the  streams  pouring  into  the  upper  Lauren- 
tian  hikes,  froin  the  surface  drainage  of  the  land,  are  hrown  and  heu  y 
v/ith  nnuh  hat  the  water  rushing  over  Niagara  remains  of  the  same  deep 
greenish-blue  tint  season  after  season  and  jear  after  year.  Niagara  river, 
ahove  the  falls,  and  the  St.  Lawrence  are  surface  streams,  l)ecause  their 
clear  •vatei'S  have  but  slight  power  of  corrasion  ;  it  is  for  tliis  reason  thnt 
during  the  centuries  they  have  occupied  their  present  channels  they  have 
not  materially  deei)ened  them. 

In  the  case  of  lakes  fed  by  the  turbid  waters  from  glaciers,  the  jjart  they 
play  as  settling  basins  is  even  more  strikingly  shown  than  in  tlie  instances 
just  cited.  Lake  (ieneva,  Switzerland,  fed  I)}-  the  silt-laden  waters  of  the 
Rhone,  is  discolored  for  several  miles  from  where  the  river  enters,  l)Ut 
when  the  waters  leave  the  lake  and  again  start  en  their  journey  they  are 
wonderfully  clear.  An  abuiulance  of  similar  illustrations  are  furnished 
by  tlie  glacial-fed  lakes  of  the  Sierra  Nevada  and  Cascade  mountains  and 
by  some  of  the  numerous  lakes  on  the  head  waters  of  the  Yukon. 

The  streams  flowing  from  lakes  are  not  always  clear,  however,  as 
exce])tions  occur  where  the  outlets  are  so  situated  that  sliorc  currents 
may  luing  sediment  to  them.  The  construction  of  beaclics  and  embank- 
ments by  shore  currents  may  take  place  at  the  outlet  f)f  a  lake  so  as  to 
obstruct  the  escajjc  of  its  waters  and  initiate  a  struggle  between  the 
waters  tending  to  form  deposits  and  those  escaping  through  tlie  chamiel 
of  discharge,  'i'he  outflowing  waters  may  thus  be  rendered  tiubid  and 
have  the  material  supplied  with  which  to  erode  their  channels.  A  case 
in  point  is  thought  to  l)e  furnished  at  the  strnth  end  of  Lake  Huron, 
where  Kiver  St.  (lair  has  its  source,  althougli  delinite  observations  on 
the  relation  of  the  outlet  to  shore  currents  have  not  been  made,  'i'l it- 
waters  of  River  St.  Clair  are  not  of  the  transparent  character  that  would 
be  ex])ected  in  a  stream  starting  from  a  large  lake ;  and  a  broad  delta  has 
been  formed  in  Lake  St.  Clair,  into  which  the  river  empties  after  a  short 
course  through  low  alluvial  lands.  The  source  of  the  material  forming 
the  delta  cannot  be  refen-ed  to  the  erosion  of  the  banks  of  the  stream,  and 
is  not  furnished  by  tributaries,  but  a[)parently  comes  from  the  action  of 
waves  and  currents  on  the  shores  of  Lak^  Huron  adjacent  to  its  outlet.' 

The  rapidity  with  which  lake  basins  in  all  parts  of  the  world  arc 
becoming  filled  with  sediment  is  sufficient  in  itself  to  show  that  no  lakes 
fed  by  turbid  streams  can  be  geologically  old.  _  ...    -...-i  ._..:,„.. 

'  These  conclusions  have  recently  bte  conlirmed  by  V.  B.  Taylor  in  an  instructive  paper 
(111  "The  Secor.il  Lake  Algoncjuin,"  Am.  Geol,,  vol.  lo,  March,  181»o,  pp.  171,  172. 


MOVEMENTS    OF    LAKE    VATERS. 


41 


iren- 
eavy 
deep 
liver- 
their 
1  tli>»t 
have 

t  they 
taiices 
of  the 
rs,  hut 
ley  are 
•nished 
us  and 

;ver,  as 

urrents 

■iiihauk- 

so  as  to 
u  the 
laniiel 
id  and 
A  case 
Huron, 
ions  on 
The 

it  woidd 
elta  has 
a  short 
forming 
earn,  and 
action  of 
mtlet.i 
•orkl  are 
no  hikes 

icthH-  papt'i 


Mechanical  sediments.  —  The  coarse  sedirnent  hrought  to  hikes  by 
streams  is  either  built  into  deltas  or  swept  along  the  coast  by  shore  cur- 
rents and  mingled  with  the  })el)bles  and  sand  derived  from  the  wear  of 
tlie  land  by  shore  waves.  The  liner  products  of  the  wash  of  the  land, 
and  of  shore  erosion,  are  carrieil  lakeward  and  deposited  in  stratitied  lay- 
ers over  the  lake  bottom.  In  general,  the  slieet  of  material  thus  sjnead  out 
is  thickest  and  coarsest  near  sliore  and  Ijecomes  finer  and  thinner  as  the 
distance  from  land  increases.  When  sedimentation  goes  on  uninterrui)t- 
edly  until  a  basin  is  filled,  the  result  is  a  more  or  less  regidar  lens-shaped 
body  t)f  sediments,  having  a  broad  central  area  of  fine  material,  which 
graduates  into  a  fringe  of  coarser  character  about  its  borders.  The  coarse 
strata  in  the  shore  deposits  overlap  and  dovetail  along  their  lakeward 
margins,  with  the  outer  l)orders  of  the  layers  of  tine  sediment  in  the  cen- 
tral i)art  f)f  the  basin,  for  the  reason  that  the  coarser  material  is  carried 
farther  from  land  during  storms  than  when  the  weather  is  i-alm.  This 
general  relation  of  coarse  shore  and  fine  off-shore  dei)Osits  is  of  interest, 
especially  in  the  study  of  extinct  lakes,  and  may  enable  one  to  draw  their 
former  boundaries  with  considerable  accuracy  even  when  all  distinctive 
features  of  their  shore  topography  have  been  obliterated. 

The  sediments  of  the  existing  lakes  of  America,  so  far  as  they  have 
l)een  studied,  are  princi[)ally  clays,  which  vary  in  character  according  to 
(he  nature  of  the  rocks  and  soils  on  the  neighboring  land.  The  sediments 
of  the  Lattrentian  lakes  and  of  lakes  generally,  particularly  in  humid 
regions,  are  characteristically  blue  clays.  The  Pleistocene  clays  of  the 
Erie  and  Ontario  Ijasins  are  tenacious  l)lue  days,  simdar  to  those  now 
accumulating  in  the  same  basins;  but  the  clays  de[)Osited  during  a 
former  Ijroad  extension  of  Lake  Superior  are  fine,  evenly  laminated  j)iids- 
isli  clays,  and  owe  their  distinctive  tint  to  the  color  of  tlie  rocks  from 
which  the}'  were  derived. 

The  sediments  now  accunuilati:.g  in  the  lakes  of  the  arid  regions, 
l)ut  more  especially  in  the  temporary  or  [)laya  lakes,  are  usually  light- 
colored,  and  have  a  yellowisli  tint  when  dry. 

In  regions  of  deep  rock  decay,  like  the  southern  Appalachians,  the 
<lebris  swept  into  lakes  would  have  the  characteristic  tints  of  terra  rosxa, 
as  the  highly  oxidized  product  of  [)rolonged  rock  decay  is  termed,  uidess 
it  was  mingled  with  organic  matter  in  sullident  (piantity  to  deoxidize 
the  iron  to  which  its  richness  of  color  is  due. 

The  generalization  that  all  lake  sediments  are  of  a  reddisli  tint,  for- 
merly advanced  by  certain  English  geologists,  does  not  find  supjiort  fioui 


42 


LAKES    OF   NOllTH    AMERICA. 


somewhat  extended  obser vatic ms  made  in  this  connection  in  America. 
In  fact,  the  blue  and  yellowish  tints  of  such  deposits  are  so  general  in  this 
country  that  the  reverse  of  the  proposition  referred  to  might  be  more 
reasonably  claimed. 

In  small  lakes,  when  sedimentation  is  retarded,  the  growth  of  mol- 
lusks,  diatoms,  etc.,  may  j)rogress  rapidly  and  their  dead  shells  accumu- 
late on  the  bottom  so  as  to  exceed  the  amount  of  mechanical  sediment, 
and  shell  marl  and  diatomaceous  earth  be  formed.  This  process  is 
especially  well  marked  in  lakes  that  are  surrounded  by  matted  vegetation 
througli  which  the  inflowing  waters  percolate  and  are  filtered  of  nearly 
all  material  in  suspension.  As  the  growing  mosses  encroacli  on  lakes  of 
this  character,  a  layer  (tf  peat  is  formed  above  tlie  marl  and  a  well-marked 
stratification  results.  Layers  of  [)tnit  above  strata  of  shell  marl  may  be 
seen  in  process  of  accumulation  in  many  of  the  small  lakes  of  Michigan 
and  otlier  similar  regions.  In  lake  and  svvam[)  deposits  that  are  now 
drained  and  utilized  for  farming  [)ur[)oses,  a  layer  of  white  niiarl  beneath 
black  humus,  is  frecpiently  exposed.  Tliese  deposits  have  an  additional 
intei'est  from  the  fact  that  we  find  in  them  the  bones  of  the  mastodon, 
mannnotli,  giant  beaver  and  huge  sloth-like  animals  that  roamed  over 
North  ^Vmerica  in  recent  times,  but  are  now  extinct. 


(- 

c 


< 

(3 

I 
O 


LJ 

< 


Q 
Z 
< 


O 

z 
< 


3 

o 

Q 
Z 
Z) 

o 

cc 
13 

Hi 
(T 

o 


I 
o 
< 

llJ 

03 


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o 

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UJ 

I 

a] 


o 

t 

r 
ui 


11 


CHAPTER   III. 


THE  TOPOGRAPHY  OF  LAKE   SHORES! 

The  variety  mid  beauty  of  a  landscape,  embracing  mountain^;  and  liills, 
valleys  and  ravines,  is  mainly  due,  as  is  well  known,  to  the  action  of 
running  water.  The  lines  resulting  from  this  mode  of  sculpture  are  more 
or  less  vertical.  The  waters  of  lakes  also  engrave  their  histories  on  the 
rocks,  but  the  writing  conforms  with  the  water  surface  and  is  in  horizontal 
bands.  Two  strongly  contrasted  types  of  relief  are  thus  produced,  which 
may  be  distinguished  at  a  glance.'  The  details  in  each  type  may  be 
separated  and  their  mode  of  origin  explained.  Each  feature  of  the  land 
is  thus  found  to  have  a  meaning,  and  the  pleasure  derived  from  even  the 
most  sublime  and  beautiful  landscapes  is  vastly  enhanced  to  those  who 
can  read  their  histories. 

The  work  of  rain  and  rivet's  is  outside  the  scope  of  the  present  book, 
but  the  principal  topographic  features  characteristic  of  lake  shores  will  be 
briefly  described  and  their  mode  of  origin  indicated. 


I  '*. 


if 


i  r 


The  sea  cliff.  —  Usually  the  first  features  of  a  lake  shore  to  attract 
attention  are  the  steep  slopes  which  rise  from  the  water's  edge  and  seem 
to  mark  the  boundary  beyond  which  the  waves  cannot  i)ass.  That  the 
slopes  here  referred  to  have  been  produced  by  the  waters  of  the  lake  eat- 
ing into  the  land,  is  so  apjiarent  that  it  seems  almost  a  waste  of  words  to 
explain  the  process  by  which  they  are  formed.  Their  declivity  varies  accord- 
ing to  the  nature  of  the  material  forming  the  land  and  also  in  conformity 
with  atmospheric  conditions.  When  the  shores  are  of  soft  rock  or  loose 
unconsolidated  material,  the  slopes  are  gentle,  but  when  the  shore  is  f)f 
hard  rock  they  may  become  vertical  or  even  overhanging  precipices.  In 
regions  Avhere  weathering  is  progressing  actively,  the  waste  of  the  land, 
t)wing  to  the  combined  influences  of  rain,  frost,  etc.,  may  be  more  rapid 
than  the  ei'osion  of  a  lake  shore  by  waves  and  currents;  under  these  con 
(litions  the  Muffs  bordering  a  lake  will  have  a  more  gentle  slope  than 
where  atmos[)heric  agencies  are  relatively  less  destructive.  The  name 
"sea  cliff"  is  applied  to  the  slopes  produced  by  the  under-cutting  of  lake 
shores  without  reference  to  their  declivity,  and  has  been  borrowed  from 


44 


LAKES    OK    NOKTH    AMKUK'A. 


the  nomenclature  of  the  oeeanie  shores  where  tojiojrnipliie  forms  siniihir  in 
character  and  in  ori<;fin  exist  in  nian^  [jhuH's  on  a  nia<rnilicent  scale.  Varia- 
tions in  the  appearani-es  of  sea  cliffs  in  soft  and  hard  material  are  shown  on 
Plates  8  and  1).  These  illustrations  have  heen  selected  from  a  large  num- 
her  of  photographs  taken  hy  the  writer  on  the  horders  of  the  Laurentian 
lakes,  and  illustrate  the  two  tvi)es  of  shore  features  there  most  iironounceil. 
Tiie  recession  of  sea  cliffs  may  he  hest  studied  when  a  gale  is  blowing 
directly  on  shore.  At  such  a  time,  each  wave  as  it  reaches  shallow 
water  and  surges  up  on  the  land,  carries  foiward  the  gravel  and  sand 
within  reach  and  dashes  it  against  the  base  of  the  elift'  and  tends  to 
wear  it  away.  The  finer  products  produced  by  the  friction  and  pcmnding 
of  the  loose  stones  against  each  other  and  against  the  cliff,  are  carried  lake- 
ward  by  the  under-tow.  leaving  the  coarser  fragments  leady  to  be  caught 
up  by  the  next  inrush  of  watei'  and  the  process  repeated.  As  the  cliff  is 
under-cut,  fresh  angular  fragments  fall  from  its  face  to  the  beach  below 
and  are  at  once  attacked  by  tlie  waves  and  sooner  or  later  reduced  to 
rotmded  gruvt'l  and  sand.  The  cliil'  thus  furnishes  the  tools  for  its  own 
destruction. 

'I'lie  manner  in  which  lakes 
wear  away  the  land  contining 
them   is  illustrated  in  the  fol- 
L^>,e:  suf^FAcc:  ,.-''  ^^^  lowing  section  of  a  rocky  shore, 

which  also  shows  the  relation 
of  the  sea  cliff  h  c  to  the 
platform  or  terrace  ac  at  its 
base. 

Waves  are  only  abb;  to  reach  the  land  in  a  narrow  vertical  interval, 
determined  mainly  bv  the  dirt'erence  in  their  heiuht  durini''  calm  weather 
and  when  storms  are  raging.  Even  in  the  case  of  large  lakes  this  inter- 
val does  not  exceed  ten  or  iifteen  feet,  and  on  account  of  the  debris 
usually  encumbering  the  shore,  the  actual  zone  of  erosion  on  the  fresh 
rock  surface  is  normally  very  much  less  than  this.  The  waves  thus  act 
like  a  horizontal  saw  cuttino-  into  the  lan<l.  The  result  is  that  at  the 
base  of  every  sea  clitt'  there  is  a  platform  or  terrace,  as  indicated  in  the 
above  diagram.  The  junction  of  the  sea  cliff  with  its  accompanying  ter- 
race is  a  horizontal  line,  deteimined  by  the  elevation  of  the  lake  surface. 
Lake  waters  unaided  by  del)ris,  like  the  waters  of  clear  streams,  have 
but  slight  power  to  erode.  It  is  only  when  the  margin  of  a  lake  is  suffi- 
ciently shallow  to  bring  the  debris  on  its  bottom  within  the  reach  of  the 


Fig.  2.  —  Puofilk  ok  a  Si:.v  Cmkk  and  Ti:iii!A(  e. 


() 


terval, 
ather 
iutev- 
lobiis 
fresh 

lis   lift 

it  tlio 
a  the 
ig  tei- 
irfaee. 
,  have 
s  suffi- 
of  the 


if 


wave 
This 
Luke 

other 

IS  sea 

the  li 

rock.s 

and  ( 

and  c 

until 

this  h 

first,  1 

and  t( 

T< 

usuall 

which 

Tl 

hound 

panyir 

ward  s 

to  exci 

are  coi 

there  i 

thickes 

feature 

compel 


On 

already 
the  lant 


THE  TOPOGUAl'HV  OF  LAKK  SHORES. 


45 


waves  that  the  land  is  cut  away  so  as  to  form  sen  cliifs  and  terraces. 
This  is  shown  in  a  striking  manner  ahin<f  large  portions  of  tl»e  shores  of 
liuke  Superior,  where  bold  clift's,  an  inheritance  from  a  previous  topo- 
L;raphic  cycle,  plunge  into  deep  water,  and  are  without  talus  slopes  or 
other  loose  deposits  within  reach  of  the  waves.  In  these  instances  tliere 
is  scarcely  a  mark  on  the  rocks  that  would  record  the  present  hoi-izou  of 
I  lie  lake  should  its  watera  be  withdrawn.  Clear  waters  may  dissolve  the 
rocks  against  which  they  dash,  however,  and  when  cliifs  of  limestone 
and  other  easily  soluble  rock  descend  into  deep  waters,  a  line  of  grottoes 
and  caves  may  be  formed  below  the  upper  wave  limit,  and  perhaps  increase 
until  a  slielf  is  produced  on  which  sand  and  pebbles  could  lodge.  When 
this  happens,  erosion  by  solution  is  assisted  by  mechanical  means,  slight  at 
tii'st,  but  increasing  as  the  conditions  become  more  favorable,  until  cliffs 
and  terraces  result. 

Terraces.  —  The  terraces  about  the  margins  of  existing  lakes  are 
usually  covered  with  the  loose  stones  and  sand,  and  form  the  beaches  on 
which  one  may  walk  during  calm  weather. 

The  surface  of  a  typical  lake  terrace  slope«  gently  lakeward  aiul  is 
bounded  on  the  landward  margin  by  the  upward  slope  of  the  accom- 
panying sea  cliff,  and  on  the  submerged,  lakeward  margin  by  a  down- 
ward slope  leading  to  deeper  water.  These  terraces  owe  their  formation 
to  excavation  or  to  deposition,  and  in  most  instances  the  two  i)rocesses 
are  combined.  Even  when  the  terrace  is  due  principally  to  excavation, 
there  is  a  surface  layer  of  rounded  debris  resting  on  it,  which  is  usually 
thickest  on  the  lakeward  margin  and  forms  the  lakeward  slope.  These 
features  are  shown  in  the  following  cross  section  of  a  lake  shore,  where  a 
compound  terrace  is  being  formed,  and  also  on  Plate  13. 


LAf(£     SU fir  ACE 


Fio.  3. —  Profile  of  a  ti'T  and  nriLT  Terkace. 


On  precipitous,  rocky  shores,  terraces  are  not  produced,  for  the  reason 
already  stated  in  considering  the  origin  of  sea  cliffs,  that  the  d^jbris  from 
the  land  falls  into  deep  water  below  the  reach  of  the  waves. 


4t5 


LAKKS   ol'    NOItTH    AMKUICA. 


vi 

m 

' 

' 

It 

Kcjfcrciico  lias  iilroiuly  In-cii  iiiiulc  to  tlie  iictioii  ol'  \\\v  Wiivcs  wlii'ii  tin 
wiiifl  hlows  (liri'ctly  on  shore.  'J'lie  rt'tuni  ciirrt'iit  is  thuii  uii  uiidurtow 
llowiii}^  lakt'Wiiid.  When  the  wind  hlows  ii^Minst  the  shore  at  a  low 
anj^'le,  however,  currents  are  estahlished  which  travel  along  the  lake 
niarjrin  and  Hwccp  the  loose  material  on  the  surface  of  tlie  terrace  with 
thenj.  These  currents  have  many  of  the  features  of  streams,  and  greatly 
increase  the  power  of  waves  to  erode  the  land.  The  upward  movement 
of  waves  lends  to  lift  loose  material  within  their  reach  and  the  lattiral 
movement  of  currents  to  transport  it.  The  loose  material  at  the  base  ol 
sea  cliffs  is  thus  carried  along  the  beach  by  shore  currents  in  one  direction 
or  another,  according  to  the  direction  of  the  wind,  and  deposited  so  as  to 
fcn-m  accumulations  of  varicms  characiter. 

When  a  headland,  with  a  beach  at  its  base,  is  flanked  on  either  hand 
by  low  shores,  the  debris  falling  from  its  face  is  carried  along  by  the 
shore  currents  an<l  built  into  terraces  adjacent  to  the  land  or  de|)osited  so 
as  to  form  free  embankments  or  lid-  it  some  distance  from  the  original 
shore.  That  this  pioccss  is  of  connuon  occurrence  may  be  shown  on 
many  lake  margins  by  examining  the  material  forming  rocky  headlands 
and  comparing  it  with  the  stones  on  neighboring  beaches.  In  such  in- 
stances the  rtH'k  fragments  at  the  base  of  the  cliff  will  freipiently  be 
found  to  be  large  and  angidar  and  to  become  smoother  and  more  anil 
more  rounded  the  farther  they  are  traced  from  their  jjarent  ledges. 

Terra(!es  and  marginal  embankments,  built  wholly  of  gravel  and  sand, 
maj^  also  be  formed  on  low  shores  by  the  washing  u[)  of  loose  material 
from  this  lakeward  margin,  thus  deepening  the  water  on  the  outside  ol 
the  shelf. 

The  transportation  of  debris  along  the  surfaces  of  terraces  by  tlie  com- 
bined action  of  waves  and  currents,  and  its  deposition  when  dee})  water  is 
reached,  leads  to  the  formation  of  structures  of  various  forms,  known  as 
embankments. 


liliiibanknioiits.  —  This  name  has  been  adopted  for  free  ridges  of 
loose  material  built  by  currents  about  the  margins  of  water-bodies.  They 
have  the  general  form  of  railroad  embankments,  and  their  level  crests  in 
most  instances  rise  from  a  tew  inches  to,  perhai)s,  three  or  four  feet  above 
the  calm-weather  surfaces  of  the  water  in  which  they  occur.  The  ten- 
dency of  built  terraces  to  change  to  embankments  on  low  shores  has  alrcad\ 
been  noticed,  Init  the  most  typical  examples  occur  where  shore  currents, 
having  an  abundance  of  loose  material  at  their  command,  are  deflected 


I'll    i\\v 

U'llow 
a  low 
e    liikr 
•e  witli 
•  rrcath 

Vt'llU'llI 

lateral 
basil  of 
ireotioii 
so  as  to 

liY  ham  I 
by  llir 
)siti'il  so 
original 
lown  on 
badlands 
siu'h  iii- 
cntly  be 
I  ore  ami 

(l  sand, 
material 
itside  ol 

the  coiu- 
Avater  is 
nown  as 


idges  of 
.  Tlu-v 
'rests  in 
et  above 
'he  ten- 
ah-ead) 
•urrents. 


o 


<        5- 


h- 


LU 


iD 


LU 


UJ 


>         3 


O       5 

CO         >" 


^      -z 


^         3 


03 


Ikflect 


eu 


w 


il 


TMK   TOl'OUUAI'IIY    OF    LAKK   SIlnUKS. 


47 


into  (k'cp  water  and  thus  lose  their  power  to  truiis|»orl.  The  variiitioiis 
111  tlie  Hhapes  of  eiuhiiiikiiu'nt.s  Iiiive  led  to  tlie  retuiriiitioii  of  various  inore 
or  U'ss  s|)eeili(!  forms,  sueh  as  sjuts,  U>ops,  liars,  \'-hars,  etc.,  some  of  wiiicli 
are  descriiu'd  In-low. 

The  liuihhiijr  of  eiiiliaiikiiH'iits  «iiii  he  best  sludifd  where  tlieri'  is  an 
iihrupt  ehaii^'e  in  tlie  (hivitioii  oi  the  sliore  adjaceut  In  a  locality  where 
the  formation  of  a  sea  elitf  and  its  aeeonipanyini;  leri-aee  is  in  progress. 
Such  an  instance  is  illustrated  in  the  following  sketch-map  : 


Fio.  4.  —  Skkt(Ii-mai>  ok  ax  Kmhaxkmknt. 


The  shore  on  the  right  of  the  cove  i.s  steep  and  forms  a  sea  cliff  that  rises 
ahove  a  terrace  along  which  the  current  travels  in  the  dii'cetion  indicated 
liy  an  arrow.  Shore  currents  follow  the  liidadei'  outlines  of  the  laml.  hut 
(lit  across  jjays  and  inlets.  For  this  ivason,  in  the  case  hefoie  us,  the 
sand  and  gravel  swept  ah)ng  the  suiface  of  the  terrace  is  carried  into 
deep  watei-s  and  is  dejiosited  when  the  direction  of  the  shore  changes 
ahruptly,  as  the  How  of  the  water  is  then  checked.  The  terrace  is  pro- 
longed as  an  emljankment,  having  the  same  level,  and  is  lengthened  hy 
material  carried  ah)ng  its  surface  and  deposited  at  its  distal  extremity, 
i'he  construction  of  such  an  endianknient  is  analogous  to  the  mannei' 
ill  which  railroad  endiankments  are  made  hy  carting  dirt  along  them 
fiom  a  cut  and  dumjiing  it  at  the  end  of  the  unfinished  structure,  in 
cross  sections  an  endjankment  .shows  a  more  or  less  perfect  arcrhing  of  the 
material,  and  fornnng  v/hat  may  he  termed  an  "anticlinal  of  deposition." 

In  the  ideal  illustration  here  presented,  it  is  evident  that  a  continu- 
ation of  the  i)rocess  would  result  in  the  i)rolongation  of  the  endjankment 
until  it  touched  the  shore  at  the  left  of  the  hay.  The  outline  of  the  lake 
would  then  he  simpliiied  and  a  lagoon  formed  behind  the  cndiankment. 
Should  a  stream  enter  such  a  lagoon,  the  water  escaping  from  it  might 
keep  a  channel  ojien  to  the  lake,  but  a  struggle  would  ensue  hetween  the 
shore  currents  tending  to  close  the  hreak  and  the  outflowing  water 
striving  to  keep  it  oj)en.  Eddies  in  the  conflicting  I'urrents  would  result 
and  lead  to  changes  in  the  outlines  of  the  embankment. 


fw 


il 


if 

.  ir 

;i 


Ifr 
if. 


iIHE' 


48 


LAKES    OF    NOllTH    AMERICA. 


If  ■! 


^1 


J      ■:''! 


m 


When  a  structure  like  that  (lescril)e(l  above  is  incom})lete  and  projects 
l"om  the  sho'-e  like  an  xmtinished  raih'oad  embankment,  it  is  teimed  a  sjoiV. 
An  iUustration  of  such  an  inst  iice  observed  on  the  shore  of  Au  Train 
island,  Lake  Superior,  is  shown  in  Plate  11.     See  also  Plates  2,  3  and  4. 

When  an  embankment 
spans  the  entrance  of  a  bay 
so  as  to  shut  it  off  more  or 
less  com])letely  from  the 
main  water  body,  it  is 
termed  a  bar,  in  accord- 
ance with  the  custom  f)f 
mariners  in  designating 
such  obstructions  to  navi- 
gation. Maps  of  bars  on 
the  shores  of  lakes  Su- 
perior and  Ontario  are  re- 
produced in  Figs.  5  and 
6,  from  the  maps  of  the 
U.  S.  Lake  Survey.  The 
manner  in  which  these 
were  formed,  as  well  as 
their  various  modifications 

ViV..   5.   -MA..  .,F   HA.NI.   HAK.S:    WICST  KSU  OK  LAKK   SLLEUIOH.      ^^^  ^^^^^-^^^  ^^^^^   .J^^  preSCUCe 

of  channels  across  them  in  certain  instances,  will  be  understood  from  the 
description  of  a  more  simple  example  just  given. 

The  end  of  a  spit  is  frequently  turned  toward  the  shore,  owing  to  a 
deflection  of  the  current  that  Ijuilt  it,  or  to  the  opi)osing  action  of  two 
or  more  currents,  and  becomes  a  hook,  as  is  illustrated  on  Plate  12. 
Again,  where  the  hook  is  more  pronounced  and  the  distal  end  of  the 
structure  touches  the  shore,  as  happens  oci-asionally  Avhen  there  are  only 
slight  changes  in  the  direction  of  the  coast  line,  a  loop-bar  or  V-bar  results. 

In.  brief,  it  may  be  said  that  the  waves  and  currents  of  lakes  have 
the  power  of  excavating  cut  terraces  along  the  shores  confining  them  and 
of  carrying  away  the  waste  from  the  cutting,  together  with  similar  mate- 
rial contributed  by  streams,  and  of  building  it  into  terraces  and  embank- 
ments of  various  forms  adjacent  to  neighboring  shores. 

l>eltiiH.— Where  streams  lu'ing  to  r.  lake  more  detritus  than  is  carried 
away  by  shore  current.-5,  accumulation  takes  place  and  an  addition,  termed 


ili|ji!i!]|!i|piiliiijl!!!li!ifli!mn|iii]i™^ 


ig  to  a 

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THK   TOPOGRAPHY    OF   LAKIC   SHOPwES. 


40 


a  delta,  is  made  to  the  land.  The  most  instructive  deposits  of  this  nature 
occur  where  high  grade,  streams  enter  a  lake,  as  when  a  lake  washes  the 
base  of  a  mountain  range.  In  such  an  instance,  pebbles  and  water-worn 
])oulders  are  swept  along  by  the  stream  until  it  mingles  with  the  quiet 
lake  water,  where  its  velocity  is  checked  and  the  coarser  portion  of  its 


'^    ^   . — .  ~y~^ — --I '  V..i,._ 


S7   ' 


Flu.  G  —Mai-  of  sand  bars:  soi'th  siioke  OP  Lake  Ontario. 


load  dropped ;  fine  sand  is  carried  beyond  and  deposited  about  the  outer 
margin  of  the  accumulation  of  l)oulders  and  pebbles,  and  the  finer 
niaterial  held  in  suspension  is  transported  still  fartlier  fiom  shoic  and  dis- 
tributed over  the  lake  bottom.  Tlie,  coarse  material  is  deposited  alM)ut 
the  moutli  of  tlie  stream  in  a  semi-circular  i)ile,  the  1)ase  of  wliicli  is 
l)cneath  the  water  and  the  apex  t-'.mw  distance  al)ove,  wlicre  the  stream 
iK'gins  to  lose  velocity.  The  j)iU'  is  l)uilt  out  in  all  directions  in  which  tlie 
water  has  freedom  to  flow,  and  a  s<'mi-circular  or  ocjcasionally  a  truly 
delta-shaped  addition  is  made  to  the  land. 

Fine  examples  of  deltas,  Imilt  by  swift  stieams  adjacent  to  a  precii)i- 
lous  shore,  occur  on  the  west  side  of  Seneca  lake,  New  York,  near  Wat- 
kins.  In  these  deltas  the  action  of  shore  currents  fn,m  both  tlie  north 
and  south  is  conspicuous,  and  the  deposits  have  l>een  cut  away  so  as  to 
leave  a  triangular  or  markedly  delta-shaped  outline,  but  the  apex  of  each 
"  delta "  points  lakeward,  instead  of  toward  the  shore  as  is  the  normal 


jiyMiiuMWMiiiiiniiBnaii 


60 


LAKKS    OF   NOJITH    AiMEKICA. 


condition.  About  the  niarjrins  of  these  deltas  there  are  sniall  gran4'  ^0j^ 
that  are  fre(iuently  h)0[)ed  and  enclose  la<i[oons.  An  active  atnv/^ie  j.^ 
there  in  prooivss  between  the  outdo\vini>'  streams  and  the  shoi-'  cu/i'<'ntx. 
which  has  niodilied  the  form  of  the  deltas  in  the  peculiar  way  yt*t 
referred  to. 

^V  delta  advances  as  fresh  material  is  added  to  itK  outer  marjjfin,  swi/J 
at  the  same  time  the  apex  of  the  pile  rises  and  slowly  migrates  up  stream. 
Such  a  dejtosit  has  a  well-delined  structure,  due  to  its  mode  of  giowth. 
A  radial  section  made  from  its  apex  to  any  point  nn  its  jx-riphery  would 
show  three  divisions,  as  is  indicated  in  the  following  sketch  section  of  a 
delta  built  in  Lake  lionneville,  at  Logan,  Utah. 


Fig.  7.  —  Section  of  a  Delta. 


The  history  to  be  read  in  such  a  section  is  this :  the  fine,  evenly  strati- 
fied beds  beneath  the  coarse  inclined  layers  are  sediments  deposited  on 
the  lake  bottom,  but  about  the  margins  of  deltas  they  are  usually  thicker 
than  on  neighboring  lakeward  areas,  owing  to  more  rapid  depositions 
from  the  watei's  of  the  delta-forming  stream.  In  some  instances  a  broad, 
low  api'on-like  deposit  of  fine  sediment  is  formed  about  the  lakeward 
margin  of  the  delta  proper.  As  the  coarser  portion  of  a  delta  increases,  it 
advances  lake\,-ard  and  covers  the  layers  of  tine  sediment  previously  laid 
down,  and  fre(piently  causes  them  to  become  folded  and  wrinkled  and 
occaHionally  broken  and  faulted,  on  account  of  the  weight  of  material 
imj)Osed  u[)on   them. 

The  l)oul(lers,  gravel  and  sand  brought  down  by  a  stream  are  carried 
to  the  outer  nuargiu  of  its  (-elta.  and  roll  and  slide  down  its  siUnnerged 
lakeward  slo')c  so  as  to  fornr  inclined  layers.  The  angle  of  inclination 
of  ti!e.■^<  layers  is  the  angle  of  stability  in  water  of  the  material  fofmioi: 
them.  Where  the  deposit  is  n.Kunly  of  rounded  stone  and  gravel,  the 
angle  of  slope  is  in  the  neighborhood  of  30  to  35  degrees,  but  in  souh 
instances  is  steeper  and  the  structures  are  unstable  and  '"-'-.. rabl^^  foi 
landslides. 

The  triangular  area  shown  in  the  seetiou.  alKive  the  inoiirj  d  beiis. 
the  .subaiii'ial    [»o;tiun  (if   the  dtdta.  built   by   the   >'rean\  o.    »» -ini  i  ru.^. 


,-i,^l^ 


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In  StHlH- 
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taket 


THE  TOPOGRAl'HY  OF  LAKE  SHORES. 


51 


over  its  surface.  It  is  really  an  alluvial  cone,  similar  to  the  conical  piles 
of  debris  so  conunoii  in  uesert  valleys  at  the  mouths  of  high  grade  cartons. 
It  is  irregularly  stratified,  tlie  layers  being  inclined  at  a  low  angle  corre- 
sponding with  the  slope  of  thy  surface  of  the  structure  at  the  time  tliey 
were  laid  down. 

The  change  from  the  gently  sloping  and  irregularly  bedded  material 
of  the  alluvial  portion  or  cap  of  the  delta,  to  the  steeply  inclined  and  more 
regularly  bedded  layei-s,  marks  the  level  of  the  lake  in  which  the  dei)Osit 
was  formed.  The  outer  margin  or  periphery  of  the  delta,  is  in  a  horizon- 
tal plane  and  retains  the  same  position  as  the  delta  .idvances,  providing 
there  is  [)ractically  no  cliange  in  the  level  of  the  lake  surface.  Tlie  surface 
slope  of  the  cap  of  the  delta,  along  radial  lines  from  the  ai)ex  to  the  peri[)h- 
ery,  is  gently  concave  to  the  sky.  On  recent  examples  the  surface  is 
frequently  scored  with  radiating  and  branching  channels,  or  "distribn- 
taries,"  left  by  the  changeable  stream  that  built  the  structure.  As  a 
delta  increases  in  size  its  apex  rises  and  slowly  migrates  up  stream,  as 
already  stated,  so  that  in  large  deltas  of  liigh-gra^le  streams  the  apex  is 
frequently  well  within  the  mouth  of  the  canon  through  wliich  the  draiiv 
age  is  delivered. 

In  the  deltas  of  low-grade  streams,  like  the  Mississippi,  the  divisions 
noted  above  are  not  readily  distinguishati>le,  as  the  material  forming  tiiem 
is  fine  throughout  and  the  inclination  of  all  the  layei-s  [»  gentle. 

Should  the  surface  of  a  lake  be  lowered  after  having  stood  at  a  definite 
horizon  for  a  long  period,  the  terraces,  end)anikments,  deltas,  etc..  formed 
about  its  borders  become  conspicuous  featui-»-s  of  the  expoi*ed  land  surtace 
and  another  series  of  similar  forms  is  at  onee  begun  at  a  lower  lev**!. 
Should  another  subsidence  follow,  another  series  of  horizontal  lint^  will 
be  added  to  the  topography  of  the  shores.  A  rise  of  a  lake  -akuses 
the  submergence  of  previously  formed  shore  features,  and  they  may  l>e- 
come  covered  with  fine  sediment  or  have  other  wave  and  current-built 
structures  imposed  upon  them.  Such  changes  If^d  to  puzzling  compli- 
cations in  the  records,  as  has  been  observed  in  many  instances  where  lake 
basins  have  been  emptied  and  their  sides  and  bottoms  laid  Imre. 


Ice-biiilt  walls.  —  In  addition  to  the  topographic  features  character- 
istic of  lake  shores  thus  far  noticed,  there  are  others  due  to  the  action  of 
ice.  In  northern  latitudes  the  formation  of  sea  cliffs,  terraces,  embank- 
ments, et(;..  about  the  margins  of  lakes,  excepting  those  of  large  size, 
takes  place  mainly  in  the  summer  season.     In  winter,  when  most  small 


52 


LAICKS    OF    NOUTII   AMKllICA. 


lakes  arc  Iid/cii  over,  tlic  cxpaiisiini  ol  tlif  icr  |»iislit!s  ii|)  stones  and 
fjcravcl  aliiiin'  slidvinn'  sliorcs  and  t'Dnns  otlicr  t(»j)niri'a|iliic  features. 
Anntlici'  process  lending'  in  part  in  tiic  siinic  direction  conies  into  play 
in  tlic  spring'  wlicn  llie  ice  on  a  lake  Ijceonies  l)rokeii  and  is  moved 
hy  the  wind.  The  action  under  these  condilioiis  is  the  same  tiiat  takes 
place  on  a  nuich  larn'cr  scah-  on  tlic  shoics  of  Lal)ra<lor  and  other 
northern  lands,  where  an  ice  pack  is  driven  on  a  sladving-  Iteach  hy 
the  force  of  the  wind.  Stones  and  Ixtuhlers  are  carried  up  low  lake 
shores,  in  tiie  manner  here  noted,  and  added  to  the  ridge  formed  liy 
the  winter  exi)aiision  of  tlie  ice.  ( )ccni  leiices  of  this  character  have 
been  observed  by  .1.  15.  Tyrroll  on  the  shore  of  L^ke  \Vinni[)e<4asie.'  In 
some  instances  these  ice-built  lidges  arc  so  marked  and  apjjcar  so  mucli 
like  artilicial  walls  that  they  are  commonly  referi'cd  to  the  woik  of  man. 
In  some  observed  exaiui)les  in  the  northern  portion  of  the  Tnited  States 
and  in  Canada,  ice-built  ridges  occur  40  to  iyO  feet  from  the  water's  eduf, 
are  '20  feet  hiijh  and  broad  enough  to  furnish  convenient  roadways. 

The  formation  of  ice-lniilt  walls  about  the  margins  of  small  northeiii 
lakes  by  ice  expansion  Avas  first  exi)lained  by  C.  A.  White.^  The  i)rocess 
has  also  lieen  clearly  stated  by  Gilbert,-^  in  his  treatise  on  the  t(>pogra[)hy 
of  lake  shores,  from  which  the  following  is  quoted :  — 

"The  ice  on  the  siiifaci-  of  a  lake  exi)ands  while  forming  so  as  to 
crowd  its  edge  against  the  shore.  A  farther  lowering  of  tem[)erature 
produces  contraction,  and  this  ordinarily  icsults  in  the  opening  of  ver- 
tical fissures.  These  admit  the  water  from  below  and  by  the  freezing  of 
that  water  arc  filled,  so  that  wlien  expansion  follows  a  Hulweijuejit  jisfc 
of  temperature  the  ice  cannot  assume  its  original  position.  It  conse- 
quently increases  its  total  area  and  exerts  a  sectond  thrust  upon  the  shore. 
VN'lien  the  shore  is  abrupt  the  ice  itself  yields,  either  by  crushing  at  the 
margin  t)r  by  the  formation  of  anticlinals  (upward  folds)  elsewhere ;  but 
if  tile  shore  is  gently  shelving,  the  margin  of  the  ice  is  forced  up  the 
declivity  and  carries  witli  it  any  boulders  or  other  hxjse  material  about 
which  it  may  have  fr(»zen.  A  second  lowering  of  temperature  (h)es  not 
withdraw  the  protruded  ice  margin,  but  initiates  other  cracks  and  leads 
to  a  repetition  of  t4ie  shoreward  thrust.  The  j)roc,ess  is  re])eated  from 
time  t(j  time  during  the  winter,  but  ceases  with  the  melting  of  the  ice  in 
the  spring.     The  iic  formed  the  ensuing  winter  extends  only  to  the  water 


1  Geol.  and  N:ii.  Hist.  Surv..()f  Cftnacla.     Ann.  H<i).,  18!>0-!)1,  p.  04  H. 
*  Anini<'iin  Naturalist,  vol.  2,  IStil*.  ])i).  1  |fi~14'.). 
8  Fit'lh  Ann.  KHp.,  V.  S.  (it-ol.  Surv.,  p.  Kli). 


Vl'l- 


L  list' 

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liore. 


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le 


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TIIK   Torui.KAl'KV    VV    LAKK   SHOltES. 


r)3 


margin,  and  by  the  winter's  oscillation  of  tenipenitnre  can  be  thrust  hmd- 
wanl  only  to  a  ci-rtain  distance,  determined  by  the  size  of  the  hike  and 
tlic  local  cliiiiiitc.  There  i  thus  for  ich  locality  a  definite  limit  l)eyon(l 
wliich  tlic  pinjei'tion  of  lioulders  cannot  be  ciuried,  so  that  all  are  de- 
l)osited  ah)nj^  a  conunon  line  wliere  they  constitute  a  rid^'c  or  wall." 

Shore  walls  are  not  cons[)icuous  al)out  the  margin  of  large  lakes  for 
the  reason  that  tliey  .eldoni  freeze  over  and  also  because  the  winter's  ice 
work  is  usually  obliterated  by  the  more  active  waves  and  currents  at 
other  seasons.  They  are  not  formed  about  deep  lakes  for  the  reason  that 
such  water  bodies  do  not  become  ice-covered,  and  for  the  same  reason 
they  do  not  occur  in  warm  climates. 

In  this  brief  sketch  (»f  the  topography  of  lake  shores,  an  attempt  has 
been  made  to  direct  .attention  to  the  main  processes  by  which  the  results 
liave  been  reached,  and  to  describe  biiefly  the  character  of  some  of  the 
more  striking  forms  produced,  without  attempting  an  exhaustive  analyMs 
of  the  subject.  To  the  reader  who  would  go  farther  in  the  studies  here 
outlined,  I  most  heartily  recommend  (i.  K.  Gilbert's  attractive  j)aper  on 
the  topograi)hy  of  lake  shore,  in  the  .5th  Annual  Re[)ort  of  the  U.  S.  Geo 
logical  Survey,  and  the  more  special  volume  by  the  same  author  on  Lake 
Bonneville,  forming  Monograph  Mo.  1  of  tlie  publications  of  the  U.  S. 
Geological  Survey. 


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Corporation 


23  WSST  MAIN  STREET 

WEBSTER,  N.Y.  14580 

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CHAI'TF'J    IV. 


RELATION    OP    LAKES    TO    CLIMATIC    CONDITIONS. 


Lakes  may  be  coiiveiHciitly  dividt'd  into  two  great  elasses,  t'lesli  iiiul 
saline,  in  reference  to  the  clu  inical  conijxisition  of  tlieiv  waters.  These 
two  classes  have  no  shari)ly  delhuMl  Ixjiindary  between  them,  but  a  com- 
plete graduation  may  be  found  between  the  freshest  and  most  saline 
e\am[)les. 

A  convenient  test  for  determining  to  which  class  a  lake  should  ])e 
referred  is  to  taste  its  Avater.  If  no  saline  or  alkaline  taste  is  peree^jtible, 
it  evidently  falls  in  the  first  class;  but  if  the  })resence  of  salts  can  be 
determined  in  this  way,  it  should  be  referred  to  the  second  class. 

It  is  frequently  convenient,  however,  to  lecognize  an  intermediate 
class,  or  lirackish-water  lakes,  to  include  water  bodies  that  are  slightly 
saline  or  alkaline  to  the  taste,  but  contain  only  a  small  fraction  of  one 
per  cent  of  mineral  matter  in  solution. 

The  more  pronounced  differences  in  chemical  composition,  shown  by 
lakes,  depend  mainly  on  climatic  conditions.  Fresh  A\ater  lakes  overflow 
or  else  their  surplus  water  escapes  by  percolation,  while  saline  hdces  are 
witliout  outlets.  Exceptions  to  this  rule  may  occur,  but  the}'  are  accom- 
panied by  unstable  conditions,  and  the  j)resen'?e  of  an  outlet  to  a  saline 
lake  or  its  absence  in  the  case  of  a  fresh  lake,  are  tenn)orary  phases  that 
have  not  continued  long  enough  to  bring  about  the  changes  toward 
wiiich  they  tend. 

Fresh  lakes  occur  principally  in  humid  regions,  while  saline  lakes, 
with  the  exception  of  those  formed  Ijy  the  isolation  of  l)odies  of  sea 
water,  are  confined  to  regions  of  small  rainfall.  Wliether  a  lake  shall 
overflow  or  not,  depends  ordinarily  on  the  relation  of  the  rainfall  over  its 
hydrographic  basin  to  evaporation  from  the  lake  surface.  As  lakes  fre- 
(juently  receive  the  Avater  of  fissure  s[)riiigs,  the  sources  of  Avhich  may  lu; 
far  distant,  it  will  be  mo"e  exact  to  say  that  whether  a  lake  held  in  an 
impervious  basin  shall  overflow  or  not.  depends  on  the  ratio  of  thv'  amount 
of  water  contril)uted  to  it  to  the  amount  evaitorated  from  its  surface.  If 
the  inflow  is  in  excess  of  v'va])oration.  the  water  will  rise  aiid  its  area 
increase  until  an  equilibrium  is  estaV)lished  or  until  an  outlet  is  found. 


RELATION    OK    LAKES   TO    CLLMATIC    CONDITIONS. 


55 


Wlieii  eva[)oriitioii  couiiteilHilances  the  inflow  fur  a  loiiir  poriod,  tlu; 
watei-s  are  concentrated  and  become  cliarged  with  mineral  matter,  for  the 
reason  that  all  streams  and  s[)riiigs  contain  foreii,'n  snhstances  in  solntion 
which  are  left  when  evaporation  takes  ])lace. 

It  has  been  found  by  observation  that  in  re^'ons  where  the  topo},n'ai)hic 
conditions  are  favoi-a'le,  a  rainfall  of  about  '20  inches  per  year,  niul  an 
evaporation  from  lake  surfaces  in  excess  of  50  inches  per  year,  is  fri'- 
([uently  accomjjanied  by  the  formation  of  lakes  that  <lo  not  rise  sutliciently 
to  tind  an  outlet.  When  the  difTerence  in  the  direction  indicated  betv.'een 
precipitation  and  eva|)oratioi>  is  still  f>'reater,  (>r  when  the  area  from  which 
a  hd<e  receives  the  drainiinc  is  small  in  reference  to  the  area  where  i  lake 
would  naturally  form,  desiccation  may  be  complete  and  permanent  lakes 
rendered  impossible. 

Whether  a  lake  shall  l)e  fresh  or  saline  depends,  therefore,  on  climatic 
conditions  and  on  the  conhguration  of  its  hydrographie  basin. 


Fresh  Lakes. 

Material  in  Solution.  —  ^\s  all  fresh  lakes  may  be  considered  as 
the  exi)ansions  of  streams,  their  chemical  composition  is  indicated  where 
the  acttial  lake  waters  have  not  been  analyzed,  by  the  comi)osition  of  the 
streams  flowing  to  or  front  them.  It  follows,  therefore,  that  the  average 
comj)osition  of  the  waters  of  fresh  lakes  would  be  shown  with  consider- 
able accuracy,  by  the  average  composition  of  the  principal  rivers  in  the 
region  where  they  occur. 

Analyses  of  the  waters  of  20  of  the  principal  rivers  of  the  United 
States  have  shown  that  they  contain  on  an  avt-rage  0.1')(>44  part  per 
thotisand  t»f  total  solids  in  solution,  of  which  0.0o<l4ir»  pjut  [ler  thousand 
is  calcium  carbonate.  This  may  be  taken  as  the  average  composition  of 
the  fresh  lakes  of  this  country,  but  more  particularly  of  those  in  the 
humid  regions. 

'n  a  table  of  48  {.na^.yses  of  Euro))ean  I'iver  waters  given  in  Bischof's 
(I'.emical  Geology,  the  average  of  total  solids  in  solution  is  0.2127  and 
the  average  of  calcium  carlxtnate  0.118'.*  ))art  per  thousand.  From  the 
analyses  of  the  waters  of  3(5  European  rivers  given  in  Roth's  Chemical 
(leology,  including  some  of  those  mentioned  by  IJischof,  the  average  of 
total  solids  is  0.2083  and  of  calcium  carbonate  (l.(»!tr)()8  part  per  thousand. 

In  both  American  and  European  rivers,  as  determined  from  the  fibove 
data,  the  average  of  total  solids  in  solution  is  0.1 888  and  of  calcium  car- 


50 


LAKKS   OF    NOUTH    AMKItlCA. 


^1 


l)onate  0.0887(55  })art  per  thousand.  These  Hj^ures  may  be  safely  as- 
sumed to  represent  tlie  average  amount  of  impurities  carried  by  normal 
streams,  and  eonseipu'utly  indicate  tlie  eliaraeter  of  the  lakes  to  or  from 
which  they  flow.  The  drainap^e  in  mountainous  n'oions,  especially  where 
supplied  by  melting  snow  and  ice,  may  be  puii-r  tlian  these  li_nures  indi- 
cate :  wliile  in  arid  ivt^ions.  wliere  el'liorescent  salts  frecpiently  whiten  the 
surface,  the  streams  arc  more  liiohly  char<fed  with  saline  matter  than  when 
the  rainfall  is  abundant.  It  is  to  be  observed  that  material  carried  by 
streams  in  suspension  is  imt  included  in  tlie  above  considerations. 

'J'he  reader  may,  perhaps,  conclude  from  the  figures  just  given  that 
the  percentage  of  saline  matter  carried  in  solution  by  (mlinary  streams  is 
luiimportant  and  of  but  little  signiticance  in  connection' with  the  study 
of  lakes.  It  is  true  that  the  amount  of  foreign  matter  in  solution  in  a 
few  gallons  of  river  water  is  small,  but  where  the  volume  of  rivers  is  con- 
sidered the  amount  oi  solid  sul)stances  carried  by  them  in  solution,  even 
in  a  single  year,  becomes  truly  startling.  Knowing  the  volume  of  a 
stream  and  the  [lercentage  of  mineral  matter  it  contains,  one  can  readily 
compute  the  weight  of  the  matter  it  carries  in  solution  in  a  delinite  time. 
This  comi)utatiou  has  been  made  for  a  few  ^Vmerican  rivers.^ 

The  average  flow  of  Croton  river.  New  York,  is  400,000.000  gallons 
daily.  In  this  volume  of  water  there  are  183  tons  of  mineral  matter  in 
solution,  of  which  47  tons  are  calcium  carbonate. 

The  Hudson  carries  daily  about  4,000  tons  of  matter  in  solution,  of 
which  more  than  1,200  tons  are  calcium  carbonate. 

The  Mississi[)i)i  carries  to  the  (nilf  of  ^Mexico  in  a  single  year  about 
113  million  tons  of  mineral  matter  in  solution,  of  which  over  50  million 
tons  are  calcium  carbonate. 

These  estimates  are  only  ap[>roximately  correct  as  they  depend  in 
most  instances  on  a  single  analysis  and  on  a  small  iuiml)er  of  nieasure- 
nu'uts  of  volume. 

The  invisible  loads  carried  by  rivers  are  not  only  of  interest  in  con- 
ne'tion  with  the  study  of  lakes,  more  esi)ecially  of  saline  lakes,  but  oi»en 
a  wide  lield  of  research  in  reference  to  the  chemical  deiuidation  of  the 
land,  the  comi)osition  of  ocean  waters,  and  the  source  of  the  material, 
more  particularly  of  the  calcium  car])onate.  secreted  by  marine  plants  and 
animals.  Into  tiiis  1)roadcr  domain,  however,  to  which  our  subject  leads, 
we  may  not  now  enter. 

1  The  (lata  from  wliic'i  tlii'  fitcts  licit'  stated  were  ol)taiuecl,  as  well  as  similar  infovmation 
concerning  otluT  streams,  i.s  yiveu  in  Monograph  No.  11,  I'.  8.  (ieol.  Snrv.,  ])[\.  172-17'). 


liELATlON    OF    LAKKS    TO    CLIMATIC    CONDITIONS. 


57 


Types  of  Fuksh  liAKEs. 

Of  the  tens  of  tliousautls  of  fresli  hikes  scattered  over  North  Ameriea, 
and  esiiccially  abunihint  in  the  iirevionsly  trhieiated,  nortlieasterii  i)or- 
tion  of  the  continent,  or  forniin<>-  a  jiart  of  tlie  more  impressive  scenerv 
of  the  Cordilleian  rej^ion,  many  mi<;ht  he  seh'cted  as  types.  Atten- 
tion will  lie  conlined,  liowever,  to  the  (ireat  Lakes,  drained  l)y  the  St. 
Lawience,  Lake  Tahoe,  California,  and  Lake  Chelan  in  the  State  of 
Washington. 

Tlio  LainviitiiMi  lakos.  —  The  gronp  of  great  lakes  drained  by  the 
St.  Lawrence,  as  is  well  known,  contain  the  most  maoiiificent  examples 
of  fresh  water-bodies  now  existing  on  the  earth.  Lake  Snperior  still 
ifiains  its  position  as  the  largest  slieet  of  fresh  water  known,  althongh 
tlie  moi'e  recent  discovery  of  Lake  \'ictoria  Nyanza  has  bronght  a  lival 
into  the  field.  This  African  lake  is  estimated  to  have  an  area  of  about 
18,000  s(|iiare  miles,  which  is  1:^.000  s(piare  miles  less  than  the  area  of 
the  great  American  lake;  but  when  an  actual  survey  slir.ll  liave  been 
nuuh'.  it  is  ]iossi])le  that  this  difference  will  be  materially  decreased. 

While  Lake  Superior  exceeds  all  other  fresh  lakes  in  extent,  it  raidvs 
second  among  terrestrial  Avater-bodles,  for  the  reason  that  the  Caspian 
Sea  is  the  largest  sheet  of  water  not  in  open  communication  with  the 
ocean,  now  existing.  The  Caspian  is  saline,  liowever,  and  falls  in  the 
second  irreat  division  of  lakes  here  recofjni'/ed. 

The  orii^in  of  the  basins  of  the  Laurentian  lakes  has  been  referred  to 
in  Chapter  L  in  connection  with  the  action  of  glacial  agencies  in  obstruct- 
in.g  drainage;  an  account  of  their  i)ast  history  is  given  in  advance  ii'  dis- 
cussing the  I'leistocene  lakes  of  the  same  region ;  at  present  atteni'ou 
will  be  confined  to  some  of  the  more  interesting  features  of  the  existing 
lakes. 


The  U.  S.  Lake  Survey.  —  A  survey  of  the  Laurentian  lakes  was 
made  by  the  Corps  of  Engineei's.  C  S.  Army,  l)etween  1841  and  18M1, 
and  is  known  as  the  l'.  S.  Lake  Survey.'  On  the  maps  or  chart  published 
l)y  that  survey,  the  outlines  of  the  shores  of  the  lakes  and  of  their  con- 
necting Avatei-s  are  given,  together  with  the  tt)pography  of  a  narrow  strip 
of  the  adjacent  land;   the  de[)th  of  water,  character  of  bottom,  etc.,  as 

'  Ht'ljovt  upmi  the  rriiiiary  'rriiuiguhuiun  of  the  U.  S.  Lake  Survey,  by  Lieut.-Col.  C.  B 
Comstock,  Washinjrti'n,  lS8'i. 


w 


68 


LAKKS   (»!•■    N(>I;TM    AMKIMCA. 


<lt;tc'niuiio<l  troin  tliousiinds  of  soniiduitf.s,  is  also  iiidit'att'd.  Tliis  cxct'lU'iit 
survey  is  i\w  basis  of  iieaily  all  accurate  iufonuatiou  now  acccsssihle  con- 
cerning tlie  physical  features  of  the  lakes  in  (question,  and  has  been  freely 
used  in  compiling  the  following  statements. 

Owing  to  changes  in  the  rivers  connecting  the  various  Laurentian 
lakes  and  in  liays  and  i-avigalde  channels,  and  also  on  account  of  the 
many  harl)or  and  canal  imi)rovemcnts  that  liavt;  been  made,  a  new  survey 
of  portions  of  these  lakes  has  been  found  necessary,  and  is  now  in  i)rog- 
ress  under  the  direction  of  (ieu.  O.  M.  l'o(\ 

The  area  of  the  Laurentian  lakes  has  been  determined  with  approxi- 
mate accuracy  from  measurements  made  on  the  maps  of  the  U.  S.  Lake 
Survey.  'I'he  results  of  these  measurements  by  different  individuals 
vary  somewhat,  biit  those  pulilished  by  L.  V.  JSchermerhorn^  are  here 
ado[)ted. 

AuKA  <»K  Tin:   r.Ari!KNHA.\  Lakks  i\  S(jrAUK  Mii.ks. 


Watkk  Si  k- 

FACK. 

Wateb  Sued. 

HvDiioouAriiie 

liA.SI.V. 

Lake  Superior 

;n,2oo 

51,000 

82,800 

St.  Miirv's  river 

1.50 

800 

!).")() 

Lake  Mieliinaii •     . 

•->2.t50 

.•J7,700 

G(M50 

Lake  Uiiroii  ami  ';e()rt;iaii  liay 

2:5,800 

:n,7oo 

55,500 

St.  flair  river           

25 

;5,800 

;}.825 

Lake  St.  Clair 

410 

3,400 

;5,810 

Detroit  river 

25 

1,200 

1,225 

Lake  Erie        

f).()fiO 

22,700 

;32,(i(i(t 

Niagara  ri\('r 

15 

;500 

;5i5 

Lake  Ontario 

Total 

7,240 

21.()00 

28,840 

!).'),275 

174,800 

270,075 

The  volume  of  water  tiowing  through  the  rivers  draining  the  various 
lakes  is  on  an  average  as  follows: 


St.  ]\Iary"s  river,  the  outlet  of  Lake  Superior 

St.  Clair  river,  the  outlet  of  Lakes  Huron  and  Michigan 

Niagara  ri\er.  the  outlet  of  Lake  Erie 

St.  Lawrence  viver,  tlie  outlet  of  Lake  Ontario  .         , 


Crnic  Fkkt 

I'KR  SKCONI). 

8(i,000 

2:55,000 

2(15.000 

;5oo,ooo 


1  "Physical  Features  of  the  Northern  and  Xorthwesteru  Lakes,"  Amer.  .Four.  Sci.,  M 
sec,  vol.  :W,  1887,  pp.  278-284. 


|l     1 


UKLATION    OK    LAKKS    TO    CIJ.MATIC    CONUITIONS. 


59 


Tlie  mean  elevation  of  tlic  sinfiiccs  of  tlic  ryauveiitiaii  lakes  above  the 
sea,  their  maxiinum  depth,  etc.,  as  shown  by  soundiiii^s,  are  as  follows  : 


Mkan  Kr.r.vMiox  and  .Maximi  m   Dkj'tii.  ktc.  ok  thk   Laikkntian   Lakks. 


.150 

,5(10 

,82.') 

810 

2,(t(iO 
Ji.") 

8,8-10 


r(),07o 


various 

UK-  Fkf.t 
;k  Sk<:<>nI'. 
SCi.OOO 
:!."),()()() 
'(i.'),(tOO 
00,000 

•.   Sci.,  3(1 


JlKAN  Klkva- 
rio.v. 

Ai'i'imxiMATi': 

AlKAN   1»E1'TH.  . 

Ma. MM  CM 
ln:irii. 

DrpTii  UK 

15AMIN    Mll.DW 

Ska  Lkvkl. 

Lakf  Erie 

f.jikc  Unroll       .... 
I-iiki'  Miclii,i;an      .     . 
Lake  Ontario    .... 
Lake  Suiierior  .... 

.")81 

r)8i 

217 
002 

70 

2r)0 

'M)i) 
-17.-) 

210 
7:50 
870 
738 
1,008 

140 

2H0 
1!M 

KM) 

The  average  disehai-ge  of  tlie  lakes  is  stated  by  Schermerhorn  to  be 
double  that  of  the  Ohio  and  nearly  ecjual  to  one  half  the  dis('hai<re  of  tlic 
iMississijipi.  The  area  of  the  Laurentian  basin  is  a  third  larn'cr  than  tlie 
liydroyra[)hie  basin  of  the  Ohio,  or  about  a  fifth  of  the  cornbinL-d  areas 
of  the  basins  of  the  Mississijipi  and  its  atHuents.  The  outflow  of  tlu;  St. 
Lawrence  basin  is  slightly  less  than  half  its  rainfall,  while  on  the  Missis- 
sijtpi  and  Ohio  the  discharge  is  about  a  fourth  of  the  lainfall.  if  the 
average  discharge  of  the  Laurentian  lakes  passed  through  a  river  one  mile 
wide  \\ith  a  mean  velocity  of  one  mile  per  hour,  such  a  river  would  have 
a  dejith  of  40  feet  from  shore  to  shore. 

The  volume  of  water  in  the  Laui'cntian  lakes  is  aliout  0.000  cidiie 
iniles.  of  which  Lake  Sujierior  contains  somewhat  less  than  one  half. 
I'erha})S  a  better  idea  of  this  volume  may  be  obtained  when  it  is  said  that 
it  is  sufficient  to  sustain  Niagara  falls  in  their  present  condition  for  about 
100  years. 

The  mean  annual  rainfall  of  the  St.  T^awrence  basin  is  about  31 
inches  ;  and  the  mean  de[)th  of  water  evaporated  from  the  suifaces  of  the 
lakes,  between  20  and  80  inches.^  The  amount  of  [irecipitation  on  the 
water  surface  is,  therefore,  nearly  compensated  by  the  amount  evaporated 
from  the  same  area. 

Clieinistry  of  tho  waters  of  the  St.  T^awrence.  —  The  composition 
of  the  waters  of  the  Laurentian  lakes  is  shown  with  approximate  accuracy 

1  Thomas  Hussell,  "Depth  of  Evaporation  in  the  United  States,"  Monthly  Weather 
I{eport,  r.  S.  Sifiual  Office,  Sept.  1888. 


GO 


LAKKS    OK    NOKTII    AMKKKJA. 


0* 


'l 

'1 

;i 

f 

;| 

i 

li 

.,    ^ 

L 

MB^ 

l>y  ill!  iuiiilysis  of  tlie  water  ot"  St.  Liiwrciicc  river  tiikeii  neai'  Mdiitreal. 
'I'liis  analysis  may  also  be  eoiisidered  as  represent  int.';  very  nearly  tlie  ei»in- 
jiosition  of  the  materia,  arried  in  solution  hy  the  lakes  iiud  rivers  of  the 
more  humid  ixntions  of  Nir.th  Americii.' 

A.\Ai.vM>  t»i'   TiiK   Watiu  oi    St.    I>a\vi!i;.\<  k   Hivku. 
liY  T.  .Stkhuy  llr.\T.'- 


lN<iltKI>IKXTS. 

I'AHTH   IX  A  TllorSANIl. 

Sodium,  Nil        

l*(>tas,siimi,  K 

C'aleiuiii,  Cii 

Miiiiiicsiimi.  AIj;' 

Chlorin.-.  CI 

Cailiiiiiic  a(;i<l.  COg 

Siil|iliuric  acid.  SO^ 

riiosplioric  acid.  Hl'Oj 

Silica,  Si()._, 

Aluiiiiiia,  A]„0,, 

Oxide  of  iron,  KcO 

Oxide  of  .Manganese,  MnO 

Total 

.00.-)18 
.00115 
.u:V2:V.\ 
.00.')85 

.m-2i-2 

A)(WW 
.(Mis:il 

trace 
.0:{700 

trace 

•  4 
K 

0.10055 

'leaking  the  volume  of  the  St.  Lawrence  at  300,000  euhie  feet  pel' 
second,  the  comj)uted  discharge  of  Lake  Ontario,  it  follows  from  the  above 
analysis  that  approximatel}'  l.o  tons  of  mineral  matter  in  solution  is  trans- 
ported by  it  i)er  second,  or  about  50  million  tons  anuuall}'. 

Kro.sioii  of  the  lake  shores.  —  The  shores  of  the  Laurentian  lakes 
aie  being  eroded  at  many  localities,  and  the  material  thus  removed  de- 
j)osited,  in  jjart,  on  other  portions  of  the  coast  so  as  to  add  to  the  land 
area.  Some  information  in  this  connection  has  been  compiled  by  Charles 
Crosman.'  but  much  additional  data  is  required  before  general  conclusions 
of  value  can  be  reached. 

The  average  annual  recession  of  the  sea-cliff  along  the  west  side  of 
J^ake  Michigan,  as  determined  by  Prof.  Edward  Andrews  from  a  some- 
what extended  series  of  observations,  is  stated  to  be  aboiit  ')  feet :  with  a 

1  Analyses  of  the  water  of  20  rivers  of  the  Uniiiil  States  and  Canada  may  be  found  in 
Monoirraph  No.  XI,  U.  S.  (Jeolofjieal  Survey,  Table  A. 
"  (ieolo,i;ical  Survey  of  Canada,  1H(1:],  p.  ■)(')". 
"^  "Chart  of  the  Great  Lakes."     I'ublished  at  Milwaukee,  Wi.sconsin. 


ItlCLATION    ol"    LAKKS    To    ('LIMA'Iir   ('( (MUTIONS. 


CI 


inaxiinnm  at  certain  loi-alitics,  ot"  1<!  feet.  In  tlie  iit'i<flilMirli()()(l  of  Clcve- 
laiid,  Oliio,  the  mean  reeession  of  a  line  of  pnuninent  sea-elilTs  in  liniilder 
clay,  for  a  i)en(ul  of  40  years,  lias  l)een  about  ti  U'vi  per  annum. 

Ohservations  at  less  favoralile  localities  show  a  simil.ir  retreat  ot 
other  poition.s  of  the  lake  shores,  hut  delinite  (|nMntitative  ohservation.s 
have  seldom  been  recorded.  i'.nouL>h  is  known  in  a  (|nalitative  way,  how- 
ever, to  show  that  important  changes  in  the  outlines  of  these  lakes  are  in 
proj^ress.  The  waste  of  the  shore,  resultinn'  in  a  hroaih'ninjr  of  the  sur- 
faces of  the  lakes,  is  comi)ensated  in  part  hy  the  deposition  of  tiie  material 
removed  on  adjacent  area  so  as  to  I'Xtend  the  land  lakcward.  as.  for 
exaujple,  at  the  south  end  of  Lah^  Michigan,  where  heaches  and  larjj^e 
sand  dunes  have  been  formed,  and  are  still  encroachin<r  on  the  lake. 
Observations  made  by  the  writer  at  various  localities  about  tlu'  shores  of 
the  lakes,  to«!^ether  with  the  re])orts  of  othei's,  show  conclusively  that  the 
})n)cess  of  broadening  the  lakes  hy  the  erosion  of  their  shores  is  progress- 
ing more  rapidly  than  areas  are  being  reclaimed  by  deposition,  and  theie- 
fore  that  they  are  hecomiug  shallower. 


't  per 
above 
trans- 


lakes 

,ed  th'- 

le  land 

;'harlcs 

usions 

side  of 
some- 
Avith  a 

found  in 


Coimnore<^  and  lislu'rios.  —  The  importance  of  the  Tiaurentian  lakes 
as  highways  of  commerce  is  too  well  known  and  is  too  extended  a  subject 
to  receive  treatment  at  this  time,  even  if  it  fell  within  the  scope  of  the 
l)re.seiit  discussion.  Some  idea  of  the  magnitude  of  the  commerce  on 
these  inland  waters  may  be  ha<l,  however,  from  the  re])orts  of  the  ojicra- 
tion  of  the  Government  locks  at  Sault  St.  i\hirie,  which  show  that  ll,5r)7 
vessels  passed  through  them  during  the  yeai-  ending  .June  30,  1S92,  car- 
rying over  10  nullion  tons  of  freight.  The  great  importance  of  the  com- 
merce of  the  Laurentiau  lakes  Avill  he  better  ai)i)i'eciated,  by  those  Avho 
are  not  familiar  with  it,  when  it  is  comjjared  with  the  trallic;  of  the  Suez 
Canal.  In  1889,  the  latest  date  at  which  comparative  data  are  at  hand, 
nearly  three  times  as  many  vessels  passed  through  the  locks  at  Sault  St. 
^hirie  as  through  the  Suez  Canal,  although  the  latter  is  open  for  naviga- 
tion throughout  the  entire  year.  The  tonnage  during  the  same  year  was 
7,221,935  at  the  ''Sou,"  as  against  6,783,189  for  the  Suez  Canal.  The 
importance  of  the  carrying  trade  of  the  Great  I^akes  is  also  shown  by  the 
fact  that  the  tonnasre  of  vessels  constructed  on  them  each  year  for  several 
years,  has  been  al)out  equal  to  that  of  all  the  vessels  built  on  the  Atlantic, 
Pacific,  and  Gulf  coasts.  Still  more  striking  is  the  fact  that  the  amount 
of  goods  carried  each  year  on  these  inland  waters,  is  far  in  excess  of  the 
entire  clearances  of  all  the  seaports  of  the  United  States,  and  several  mil- 


w 


{'rJ. 


LAKKS    OK    NOItTII    AMKUICA. 


eI  s 


,i 


lioii  tons  ill  excess  df  tlic  coinhiiit'cl  t'oicii^n  mul  coasliil  triidt;  of  I.(iii<lt»ii 
iiiid  Liverpool. 

'I'lii'  (k'limiul  lor  still  Welter  liieililies  for  iiiler-liike  coiiiiiniiiiciilioii  lias 
led  to  tilt!  eoiistriu'tioii  of  still  lartjer  eajials  and  locks,  and  now  iniprove- 
nients  arc  neailv  coniiilcled  wliieli  will  allow  vessels  drawinif  -1  feet  of 
water  to  pass  from  iintValo  to  Duhilli.  It  is  expeeled  tlial  when  this 
iin[)r()veinent  is  made  the  trade  l)etweeu  I^ake  Superior  an<l  tht;  more 
southern  lakt's  will  he  doui)U'd  in  a  few  years.  Kar-reaehintf  plans  for 
eonneetiny  this  important  commercial  industry  with  oei-an  hit^hways  are 
under  consideiation,  and  nnist  lind  consummatit>n  in  tlu'  near  future. 

The  lisheries  of  the  Laurentian  lakes  is  another  suhject  of  great  prac- 
tical importance,  as  they  are  the  most  extensive  lake  lisheries  in  the 
world.  The  lakes  ahound  in  trout,  whiteiish.  and  otiier  food  iislies,  and 
their  shores  are  dotted  with  lishiuM  vilhii^fes.  in  which  a  hardy  poi)ulation. 
skilled  in  all  that  pertains  to  their  calling,  are  'iving  tlii'ir  hunihle  hut 
useful  lives,  and  gaining  an  ex])erient^e  which  well  tits  them  for  naval 
service  should  their  aid  hii  called  for.  The  impor'anee  of  these  inland 
lisheries  has  received  tardy  recognition  in  comparison  with  the  similar 
industries  of  the  sea  horder,  hut  they  are  a  suhstautial  elemjent  of  national 
wealth  and  claim  the  most  careful  attention  and  guidance  of  hoth  state 
and  mitioual  legislators.  The  reports  of  the  U.  S.  l"'ish  C'ommission  'h.  w 
that  over  ten  thousand  persons  ai'e  engaged  in  this  industry  :  that  the 
capital  invested  is  in  excess  of  four  and  one-half  millions  of  dollars  :  and 
that  a  hundred  million  ])ounds  of  fish  are  secured  each  year,  which  hring  to 
those  actually  engaged  in  the  work  more  than  two  and  one-half  millions 
of  dollars. 

It  may  he  noted  as  an  item  of  interest  in  connection  with  the  ])hysical 
history  of  the  Laurentian  hasin,  that  in  lakes  Superior  and  jMichigan  crus- 
taceans and  tishes  have  heen  found  that  are  helieved  to  he  identical  with 
living  marine  forms.  These  are  thought  hy  some  persons  to  indicate  that 
the  lakes  in  which  they  occur  were  formerly  in  open  connnunication  with 
the  ocean.  Considerahle  evidence,  derived  from  a  study  of  the  foi-mer 
extent  of  the  lakes,  and  of  the  fossils  in  the  sediments  of  previous 
water-hodies  in  the  same  basins,  do  not  seem  to  confirm  this  conclusion, 
however,  and  further  study  of  the  habits  and  means  of  migratioix  of  the 
species  referred  to,  is  necessary  before  their  presence  in  inland  waters  can 
be  satisfactorily  accounted  for. 

The  movements  of  the  waters  of  the  Laurentian  lakes  and  a  few  facts 
respecting  their  temperature   and   their  ii'fluence  on  the  climate  of  the 


itKLATIoN    <»!•     I.AKKS    !'( )    (LIMA  lie    (.'OMUTIO.N.S. 


68 


a<ljiicciil  land  have  alicadv  luit'ii  rcft'ireil  l(»  in  [ircccdiiii^'  diapttTs.  Scaivdy 
iiKtn"  than  a  licininiHnj;  of  their  physical  stu(l\  lias  hct-ii  made,  liowcvfr, 
and  it  is  tii  Itc  hi>i>t'd  that  they  may  s()(»n  icccivc  the  attention  in  this 
(hrt'ctiun  tiit'V  so  well  deserve!. 


>loiiiitaiii    lak<'H. 


No  account  of  the  lal^es  of  North  AnuM'ica  is  i  on 


hrevioiis 


j)U'te  tiiat  (h)t's  not  inehiih-  some   notice  of  llie  thousands  of  hasins  amid 
the   nortliern   A]>i)ahiehians,  and   in   tlie    ('(/rdilh-ras,   in   wliieli    the   most 


luaniiiticent  seeiierv  »>f  this  continent  is  n 


lleet 


t'(l 


'11 


ii'se 


awes  are 


.f  all 


sizes,  from  mere  tarns  across  which  one;  miyht  spring  with  the  aid  of  an 
alpenstock,  to  broad  plains  of  blue,  many  s(piare  miles  in  area,  and  worthy 
of  comparison  with  the  most  ix-autifnl  mountain  lakes  of  othei'  lands.  Of 
this  aUraetive  class  of  lakes  special  attention  can  only  lie  ^iven  at  present 
ti»  two  examjiles  which  are  deslined  to  he  widely  known  on  account  of 
their  many  charms.  I  rider  to  Lake  Tahoe,  i'ndiosome(l  am(>n<^-  the  peaks 
of  the  Sierra  Nevada,  and  lyin^'  partially  in  Califoi-ina  and  partially  in 
Nevada.;  and  to  a  lakt;  of  a  different  ehaiacti'r  Init  not  less  maniiilicent, 
situated  in  the  ("asiiule  inouiituins,  in  the  Statu  of  Washingtoii,  and  known 
as  Lake  Chelan. 

IaiUv  TaiKH'.  —  This  "  L^i'm  of  the  Sierra"  is  situated  at  an  elevation 
of  t)200  feet  above  the  sea  and  is  enclosed  in  all  directions  by  I'lj^ruc.,!^ 
forest-covered  mountain  slopes  which  rise  from  two  to  <iver  four  thousand 
feet  above  its  surfat-e.  Its  ex[)anse  is  nnbroken  by  islands  and  has  an 
area  of  betwuen  192  to  lUo  s(pnxre  miles.  Its  diameter  fi'om  uoith  to 
south  is  21.6  miles  and  from  ea,st  to  wt-s:  12  miles. 

On  looking  down  on  Lake  'J'ahoe  from  the  sui-roundinjr  pine-covered 
heiji^hts,  one  ])eh<dds  a  vast  plain  of  the  most  wondeiful  blue  that  can  be 
ima<>ine(L  Near  shore,  where  the  bottom  is  of  white  sand,  the  waters  have 
an  emerald  tint,  but  are  so  clear  tliat  objects  far  bem-ath  the  surface  may 
be  leadily  distinouished.  Farther  lakeward,  the  tints  ehanj^e  by  insensil»h' 
,<fradation  until  the  water  is  a  dee[)  blue,  unrivaled  even  by  the  eoh)r  of  the 
ocean  in  its  deei)est  and  most  remote  parts.  On  calm  snnnner  days,  the 
sky  with  its  drifting  cloud  banks  and  the  lunoed  nKuintains  with  their 
bare  and  usuallv  snow-eovered  sunnnits,  are  miiTored  in  the  })laeid  wateis 
with  such  wonderful  distinctness  and  su(di  accuracy  of  detail,  that  one  is 
at  a  lo.ss  to  tell  wliere  the  real  ends  and  the  duplicate  begins.  While 
Hoating  on  the  lake  in  a  boat,  the  transparency  of  the  water  gives  the  sen- 
sation that  one  is  suspended  in  mid  air,  as  every  detail  on  the  bottom, 
fathoms  below,  is  clearly  disceniible. 


m 


04 


LAKKM    OK    NoliTH    AMKItlCA. 


Ill  t'X|K'riim'ntiii^  on  the  trimspiiiciicy  of  the  wutcrs,  IMotVssor  .lolm 
LeCoiitc  t'ouiid  that  ii  wliitc  tiisc  *,)..*>  iiiclics  in  (liiiint'tcr,  when  t'astcncd  to 
a  lint!  and  lowcrt'd  hcncatli  tin-  snrt'ucc.  \\i;s  clearly  visihU^  at  a  (K'litli  ol' 
lOH  feet.  It  is  to  In-  rfinenihcrcd  tli^t  tlic  li,i,'lit  reaching  tlie  eye  in  siicli 
an  exptM'iinent  tiaverses  tlironj^li  water  twice  the  disinnee  to  wliidi  llic 
disc  is  sid)nier<fed,  or  in  the  ex|>eiiment  refeired  to,  lilti  feet.  The  miK 
instanci'  in  this  conntry  in  which  wati-rs  have  heen  '"onnd  to  he  more 
tiansparent  is  in  tno  f,'i(!at  liniestone-water  springs  of  I"'loiida. 

Soundinfifs  made  in  Lake  Tahoe  i)y  I.eConte,  as  idrciidy  stated.  <fave  a 
niaxinuini  depth  of  liii;")  feet,  l)nt  a  m(»re  detailed  survey  may  possihlv 
discover  still  more  |)rofonnd  de[)ths.  Those  measurements  show  that  the 
lake,  with  the  exce[)tion  of  Crater  lake,  ()re<,'on,  is  the  deepest  iidand 
water-hody  in  America  yet  souikIimI,  and  excee(ls  the  dt  pth  of  any  of  the 
lakes  of  Switzerland,  hut  is  not  so  deep  as  lakes  .M:,ei^dore  and  Como  on 
the  south  side  of  the  Alps. 

The  tenii)eratnre  oi)servations  made  in  Lake  Tahoe  previously  referred 
to.  furnish  an  illustration  of  the  fact  that  deep  lakes,  even  when  situated 
at  a  high  elevation  and  subject  to  low  winter  temperatures,  do  not  freeze. 
The  surface  watei-s  are  cooletl  in  winter  and  descend,  while  warmer  waters 
from  helow  rise  and  take  their  place,  thus  establishing  a  circulation,  but 
the  body  of  water  is  so  great  that  its  entire  mass  never  becomes  cooled 
sulliciently  during  the  comparatively  short  winters  to  cheek  the  upward 
circulation  and  allow  ice  to  form.  At  the  greatest  depth  reached  the 
temperature  was  39.2°  F.,  which  is  the  tem[)erature  of  fresh  water  at  its 
maximum  (Umsity;  and  from  more  extended  ohservation  in  other  lakes, 
the  water  is  believed  to  retain  this  temperature  throughout  the  year. 

Lake  Tahoe  is  sitmited  at  such  an  altitude  that  its  shores  are  bleak 
and  iidiospitablt!  during  a  number  of  months  each  year.  For  this  reason 
it  is  proljable  that  it  will  never  lie  selected  as  a  place  of  continued  i-esi- 
dence  by  anv  considerable  number  of  families,  but  durini'-  the  sunnner, 
when  the  adjacent  valleys  are  [)arch(!(l  by  desert  heat,  the  air  in  the  lake- 
tilled  valley  is  cool  and  bracing  ;  it  then  furnishes  a  charming  retreat  for 
the  dwellers  of  the  cities  of  the  Pacific  coast,  as  well  as  for  more  distant 
wandei'crs.  As  a  place  for  summer  rest  and  recreation  it  is  second  to 
none  of  the  popular  resorts  of  the  United  States  or  Canada. 

The  waters  of  liake  Tahoe  overflow  through  the  Truckee  canon  and 
form  a  bright,  swift-flowing  stream,  which  fln(l'  its  way  to  Pyramid  and 
VVinnennu'ca  lakes,  situated  2400  feet  lower,  in  the  desert  valleys  to  the 
north.     The  waters  when  starting  on  their  troubled  journey  are  as  pure 


if' 


RELATION    l)F    LAKKS    I'O   ('LIMATIC    i'ONDlTloNS. 


66 


iiinl  liin[)i(l  as  the  iiii'ltiii«,'  snows  of  moimtjiiii  viilleys  ciui  fiiniisli.  Aiialv- 
Hcs  slio.v  tli;it  tlu'v  contain  only  O.OToO  part  [h'v  tliunsund  of  iniiiciiil 
inattci'  in  solntion,  Itnt  tin'  lakes  into  wliidi  tlicy  flow  an<l  of  wliiili  llicy 
fdiin  almost  tliu  sole  sajj^ly,  arc  alkaline  and  saline  owing  to  long 
eoneentration.' 

An  exani|»le  of  an  is(»lat('<l  (Irainage  system  is  liere  fmiiislied,  enilnae- 
ing  tlie  eonl  snniniits  of  lofty  iiionntains  wlieic  the  nioistnre  of  tlie  atnios- 
jdieie  is  condensed  ;  a  inonntain  i-escivoir  wlieir  the  waters  are  stored  :  a 
swift,  clear  stream  formed  l»y  the  overllow  of  the  reservoir  ;  and  the  hitter 
lakes  whei'e  the  sti'cam  empties  and  fi'om  which  there  is  no  escape  exce[»t 
hy  evaporation.  Sneh  an  attractive  lield  for  geographical  stndy  shonld 
not  he  long  m-glected.  A  earefid  Investigatio.i  of  the  vaiions  prohleiiis 
here  assend)led  in  nariow  honnds,  wonld  form  a  thesis  of  nnnsnal  interest. 
Will  not  some  stndent  or  some  class  of  stndents  in  our  iiniversitit-s  tell 
the  world  wliat  the  monntains  and  streams  in  this  fascinating  region  are 
doing,  explain  how  the  jtresent  conditions  came  into  existence,  and  point 
out  the  results  towards  wliieli  they  are  tending? 


Ion  and 

liid  and 

to  the 

lis  pure 


Lake  Ciiolaii.  ^ — Ourst'cond  example  of  mountain  isdvcs,  selected  from 
the  large  nnmher  that  shimmer  in  the  snidight  amid  the  highlands  of  the 
Far  West,  lies  hi(hh'n  in  the  emhrace  of  the  eastwani-reaching  spurs  of 
the  Cascade  mountains  in  the  State  of  Washingtoi.,  and  until  recently 
was  so  remote  from  the  paths  ordinarily  followed  hy  man,  that  its  veiy 
name  will  sound  strange  to  many  of  my  readers. 

Where  C'ohunhia  river  crosses  Mie  arid  region  between  the  IJoeky 
mountains  and  the  Cascade  range,  making  a  vast  swee{)  aixtut  the  north- 
ern aiul  western  margins  of  an  ancient  lava  Hoo'l,  it  washes  the  l)ases  of 
the  mountains  to  the  west  and  receives  the  tribute  of  a  nundier  of  lakes, 
fed  by  the  melting  snow  on  the  higher  portions  of  the  range.  One  of 
these  lakes,  named  in  hoiu>r  of  Chelan,  an  Indian  chief  of  consideral)le 
local  renown,  -vhose  villagt!  stands  on  its  .shore,  empties  into  the  Columbia 
through  a  deoj)  tortuous  gorge  of  recent  origin  and  sends  a  swift  stream 
of  clear,  greenish-tinted  water  alxnit  two  mih'slong,  to  join  the  great  river 
in  the  adjacent  canon.  The  lake  is  a  narrow,  river-like  sheet  of  water, 
with  gentle  windings,  extending  westward  from  the  Columbia,  seventy 
miles  into  the  mountains,  and  is  bordered  on  either  hand  by  a  continiU)Us 
series  of  rugged  peaks  that  rise  from  live  to  over  seven  tliousand  feet 
above   its  suiface.     The  deep,   narrow,  treneh-like   valley,  now  partially 

1  For  analyses  of  the  waters  of  these  lakes,  see  p.  72. 


m 


LAKKS    OF    NOItTH    A.MKIMCA. 


! 


1 1.*  ^ 


water-filled,  cnntiniie.s  beyond  the  lic;iil  of  tlu'  lake  for  a  distance  of  at 
least  twenty-live  miles,  becoming,'  nioic  anil  more  wild  and  rnj^-^'ed  as  it 
nears  the  heart  of  the  hiijfhlands.  'IMie  total  lenjjth  of  this  remarkable 
valley  is  not  less  than  one  hnndi'cd  miles,  and  its  width  at  the  level  of  the 
lake  seldom  exceeds  four  miles.  . 

The  sonndinin-  line  has  shown  that  Lake  Chelan  is  over  eleven  hundred 
feet  deej),  but  its  full  (U'pth  remains  to  be  determined.  In  several  sornd- 
ings  madi!  by  the  wi'iter  in  its  central  and  westeiii  })ortio!is,  no  bottom 
was  reached  at  the  de[)th  indicated.  The  siirfi'ce  of  the  lake  is  but  dij'.j 
feet  above  the  sea,  so  that  the  bottom  of  the  trough  is  below  sea  level. 

Where  the  clear  water  of  the  hike  washes  the  jjrecipitous  walls  enclos- 
iuff  "t  there  is  no  beach,  and  scarcely  a  trace  on  the  rocks  to  show  that  it 
has  altered  the  topograi)hy  of  the  shores.  The  present  conditi(»ns  were 
initiated  at  such  a  recent  tiate  that,  practically,  the  only  changes  they  have 
}»ro(bxced  are  at  tlie  eastern  end  of  the  lake,  where  it  emcrgi's  from  the 
rocky  detile  of  the  moinitains  and  for  a  short  s[)ace  expands  between  com- 
paratively low  shores  of  gravel  and  sand.  In  this  region  high  terraces 
mark  the  former  level  of  the  water  surface. 

How  the  great  gash  in  the  mountain,  fully  one  hundred  miles  long, 
and  now  filled  for  more  than  a  thousand  feet  in  de[)tli  by  the  lake,  was 
f.»rmed,  is  n()t  easy  to  explain.  Previous  to  the  birth  of  the  i)resent  lake 
the  valley  was  occupied  by  a  large  ghu-ier  which  flowed  through  it  and 
joined  another  great  ice  stream  in  the  canon  of  the  ''olnnil)ia.  The  ice 
smoothed  the  precipices  of  rock  and  [)iled  up  moraines  on  the  moie  gentle 
slopes  at  the  east  end  of  i!ie  valley,  but  that  the  main  depression  existed 
before  the  glacial  invasion  is  evident  and  is  in  harmony  with  the  histories 
of  many  other  valleys  in  the  Cordillerai.  region.  The  valley  has  a  still 
mtne  ancient  history,  and  in  Tertiary,  or  in  part  perhaps  in  pre-Tertiary 
times,  was  excavated  in  the  hard  granite,  now  seen  in  its  enclosing  walls, 
by  the  slow  wear  of  streams.  It  is  a  stream-cut  channel,  but  where  the 
stream  rose  that  did  the  wcu'k,  or  whence  it  Uowed,  remains  to  be  deter- 
mined by  a  careful  study  of  all  the  facits  bearing  cai  the  problem. 

It  has  been  the  writer's  fo'-tune  to  pitch  his  cam[)  on  the  borders  of  both 
Lake  Talioe  and  Lake  Chelan.  As  the  scenery  of  each  is  conjured  up  in 
revery,  it  is  diflicult  to  decide  which  is  the  more  remarkable  or  which 
shouhl  have  the  first  rant  among  the  mountain  lakes  of  America.  Each 
lake  is  surrounded  by  fore.-it-covered  UKnintains  of  mi'jestic  proportions 
and  rich  and  varied  details  ;  the  waters  <»f  each  lake  are  lear  and  deep  in 
coh)r,  or  varied  by  silvery  reflections  and   iridescent  tints  where  the  not 


RELATION    or    LAKKS   TO   CLIMATIC    ("ONIHTIONS. 


07 


o-entU' 


of  both 
(i  nji  ill 
r  wliicli 
Eiu'li 
l)ovtions 
deep  ill 
1  the  Hot 


too  gentle  mountain  winds  touch  their  surfaces  ;  in  each  instance  the 
scene  is  fresh  and  niiiuiint'd.  and  has  the  charm  of  remoteness  so  welcome 
to  many  wlio  are  weary  with  the  ways  of  men. 

At  Tiilioe  the  views  are  wide  and  far-reacliing.  The  shaofgy  moun- 
tains are  jjicturesquely  groui)ed  about  the  (central  plain  of  waters  and  the 
scene  is  open  and,  for  a  mountain  stroufjhold.  mild  and  pleasing. 

At.  Lak(;  Chelan  the  scenery  is  wild  and  rugged.  Tlie  narrow  stream- 
like she<^t  of  water,  witli  gently  curving  shores,  extends  far  into  tlie 
mountains  and  cannot  be  conqnehended  at  a  glance.  Each  view,  as  one 
ascends  the  lake,  gives  suggestions  of  something  still  more  grand  beyond. 
Eacli  turn  reveals  hic'den  beauti"s  that  entice  one  on  and  on.  The 
bordering  moiiutain.s  become  more  and  more  rugged,  as  we  venture 
farth'U  into  tlieir  embrace.  Eacli  newly  discovered  peak  is  higher  and 
more  imposing  tliiin  its  predecessor  ;  until  at  the  head  of  tlie  lake,  the 
most  lofty  summits  of  the  range,  usually  white  with  snow,  can  l)e  seen  far' 
up  the  gorge  l)eyon(l  wdiere  boats  can  go.  The  narrow  valley  bottom 
beyond  the  lake  is  filled  with  majestic  trees  and  a  rich  profusion  of  lower 
vegetation  of  almost  tro[)ical  density ;  tlie  dark  vine-entangled  forest 
seems  striving  to  conceal  some  mysterious  shrine  farther  within  the 
lieart  of  the  mountains.  A  clear,  swift  stream  tlov/s  silently  beneath  the 
deep  shade  of  the  broad-leaved  sycamores;  and  from  far  witliin  the  hidden 
recesses  of  the  valley,  the  echoes  of  unseen  cataracts  i-ome  faintly  to  the 
ear.  What  wonders  exist  in  the  U])[)er  portion  itf  tlie  valley  are  not 
known,  as  they  have  been  seen  by  o.dy  a  few  white  men  and  liave  never 
been  descrilied. 

All  of  the  surroundings  of  this  wondcful  lake  are  so  fresh  and  speak 
so  strongly  of  the  untamed  beauties  of  Nature  in  lier  wildest  moods,  that 
a  visit  to  the  region  has  the  zest  aiid  fascination  of  entering  an  uiuHs- 
covered  country,  where  each  ste[)  takes  one  farther  and  farther  into  the 
unknown. 

T'he  vegetation  of  the  Cascade  mountains  is  fir  moie  luxuriant  and 
varied  than  the  flora  of  the  Sienv  Nevada.  \n  every  nook  and  corner  one 
is  sni'iirised  and  charmed  with  the  rank  luxuriance  of  tlie  gracefully 
liending  ferns,  or  the  jirofusion  ami  brilliancy  of  the  flowers.  On  the 
higher  slopes,  between  the  forests  and  the  Imre  summits  of  the  cloud- 
capped  [leaks,  the  angles  of  the  rock  are  softened  by  luxurianv  mosses  and 
lichens,  and  the  gray  of  the  cold  granite  is  brightened  by  Alpine  blossom). 

Tent  life  on  the  shore  of  either  Lake  Tahoe  or  Lake  Chelan  is  delight- 
ful.     Each  lake  has  its  own  }jeculiar  cdiarms,  but  their  influences  on  the 


£* 


!? 


• 

f  i 

-,    1 

Ml 

II 

■■;i 

V 


68 


LAKKS    OF    NORTH    AMKUICA. 


mind  are  different.  One  <>:•  the  otlier  will  be  declared  tlie  mmc  attractive 
according  to  the  temperaimnt  of  the  person  who  yields  liiniself  to  their 
influences.  Each  is  poetic,  and  will  weave  a  web  of  golden  fancies  in  the 
mind  of  its  admirer,  ^vhicll  will  be  as  nectar  to  his  thoughts  when  his  feet 
tread  other  and  less  insi)iring  })atlis. 

Owinjjf  to  th4  verv  moderate  elevation  of  Lake  Chelan,  its  climate  is 
mild  throughout  almost  the  entire  ye.a',  and  is  deliglitful  fr;<m  early  s[)ring 
to  lute  autunui.  Since  the  building  of  the  (heat  Xorthtun  raiLoad,  this 
charming  lake  of  tht  Cascades  is  cpiite  accessible.  The  traveler  leaving 
the  railroad  at  Wenatchte,  may  ascend  the  Columbia  by  steamer,  to  Chelan 
Crossing,  a  distance  of  about  forty  miles,  and  thus  see  something  of  the 
great  river  of  the  Northwest.  From  Chelan  Crossing,  a  ride,  or  prefer- 
ably a  walk  of  ttvo  miles,  will  bring  the  visitor  to  Chelan  "City"  as  a 
uni(|iie  group  of  several  hundred  "claim  shaiities"  is  termed.  The  houses 
in  this  silent  city  were  built  simply  for  the  purpose  of  acquiring  some 
sort  of  a  title  to  the  land  on  which  they  stand  and  were  never  intended 
for  habitation.  The  generous  hospitality  of  the  si)arse  population  in  this 
frontier  town  makes  up  for  their  lack  of  numlxjrs.  Every  visitor  who 
comes  to  see  the  beauties  of  the  lake  and  mountains,  of  which  the  dwellers 
of  the  region  are  justly  proud,  will  be  welcomed. 

On  the  lake  tiiere  are  small  steamers,  which  make  regular  trips  to  its 
head,  and  boats  for  sailing  and  tishing.  The  trout  in  the  lake  are  abun- 
dant and  unusually  tine.  ?dountain  goats  inhabit  the  higher  mountains, 
and  afford  s})ort  equal  to  the  chamois  chase.  Small  hotels  have  been 
built  on  the  shores  of  the  lake  for  the  accommodation  of  summer  tourists, 
fishermen,  and  hunters.  I  mention  these  details  for  the  purpose  of  assur- 
ing the  reader  that  he  will  find  traveling  easy  and  agreeable,  if  he  wishes 
to  verify  what  has  been  stated  in  reference  to  the  attractions  of  one  of  the 
wildest  and  grandest  lakes  in  xVmerica.^ 

Only  two  exami>les  of  the  mountain  lakes  of  America  have  beeu 
referred  to,  for  the  reason  that  the  sjjace  at  commrnd  does  not  permit  even 
the  mention  of  the  hundreds  of  charming  examples,  many  of  them  of 
greater  size  and  in  their  milder  fashion  as  attractive  as  those  of  the  Sierra 
Nevada  and  Cascade  mountains,  which  add  variety  and  beauty  to  tl  e  New 
England  States,  New  York,  etc.     Extending  our  survey  to  Canada,  a  still 

1  A  more  complete  account  of  the  region  about  Lake  Chelan  than  can  be  given  at  this 
time,  may  be  found  in  a  report  on  the  Upper  Cohunbia  River  by  Lieut.  T.  W.  Symons ;  ITtli 
Congress,  Ist  session.  Senate  Exeeutive  Doe.  No.  18(i,  Wiisliington,  1882  ;  and  in  a  report  by 
the  .author,  on  a  Geological  lieconnoissanee  in  Central  Washington,  U.  S.  Geol.  Surv., 
Bulletin  No.  103.  .     ^ 


RELATION    OF    LAKES   TO   C'LLMATIC   CONDITIONS. 


09 


greater  host  of  inland  water  bodies  of  almost  every  variety  imaginable, 
attract  the  attention  and  cause  our  pen  to  linger;  but  here  again  we  can 
only  say  that  tliey  belong  to  a  great  class  of  which  types  have  been  briefly 
described. 

Salixk  Lakes.  .  ,  i 

Saline  lakes  are  formed  principally  in  two  ways.  First,  by  the  isola- 
tion of  bodies  of  sea  water,  as  'vhere  a  rise  of  the  land  cuts  off  an  arm 
of  the  ocean,  or  sand  bars  or  coral  reefs  enclose  lagoons.  Second,  by 
the  concentration  i)y  evaporation  of  ordinary  river  waters  in  enclosed 
basins.     Tlie  lirst  are  of  oceanic  and  the  second  of  terrestrial  origin. 


abun- 

intains, 

been 

ourists, 

assur- 

wishes 

of  the 

^e  been 

lit  even 

lem  of 

Sierra 

e  New 

,  a  still 

en  at  this 
)iis ;  t7th 
rcpoi't  by 
1.    Suiv., 


Saline  lakes  of  oeeanie,  <»riK'in.  —  There  are  no  conspicuous  exam- 
ples of  this  class  of  lakes  in  North  America,  although  lagoons  cut  off 
from  the  ocean  by  sand  bars  do  occur,  especially  along  the  southern 
Atlantic  coast. 

A  large  lake  of  salt  water  that  was  isolated  from  the  ocean  by  a  rise 
of  the  intervening  land  formerly  occui)ie(l  the  valley  of  Lake  Cliamplain, 
but  has  been  freshened  and  its  surface  lowered  by  overflow. 

Tlie  type  of  saline  lakes  which  were  formerly  arms  of  the  ocean  is 
furnished  by  the  Caspian  sea,  the  largest  body  of  inland  water  known. 
The  observations  of  many  travelers  have  shrtwn  that  this  sea  has  been 
divided  from  the  ocean  by  the  elevation  of  the  intervening  land.  'VV.e 
climate  of  southwestern  Asia  is  arid,  and  over  large  areas  evaporation  is 
in  excess  of  precipitation.  For  this  reason  the  ('asj)ian  has  contracted  its 
borders,  in  s[»ite  of  the  large  contiilmtion  of  water  delivered  to  it  l>y  the 
W)lga  and  other  streams. 

There  is  evidence  in  the  chemical  composition  of  tlie  waters  of  ihe 
C'as[)ian,  and  in  the  topograi)hv  of  land  separating  it  from  the  lUack  sea, 
to  indicate  that  at  first  it  was  freshened  by  overflow,  as  in  the  case  of 
the  ancient  lake  of  Cliamplain  valley,  an  i.  tliat  i'.s  present  salinity  has 
resulted  i)iincipally  from  the  concentration  of  ri  vcr  wateis.  It  may  be 
considered,  therefore,  of  oceanic  or  of  terrestrial  o  'igin  as  one  chooses. 

The  Caspian  is  180, OOO  sipiare  miles  in  area,  or  nearly  six  times  the 
size  of  Lake  Superior.  Its  maximum  deiith  is  in  the  neigliborliood  of 
;].0()0  feet,  and  exceeds  the  dei»th  of  any  other  'ake  known.  It  is  with- 
out outlet.  Its  waters  contain  (!.l2m  ))arts  in  a  tliousand  of  mineral 
mattiU'  in  solution,  consisting  prin('i[!ally  of  sodium  chloride  and  mag- 
nesium suli)liate.     The  waters  of  the  ocean,  it  will   be  remembered,  coli- 


cs i^ 


70 


LAKES   OF    NORTH    AMERICA. 


tain,  on  an  average,  34.4  parts  per  tboa.sand,  or,  in  round  numbers,  3.5 
per  eent. 

One  of  the  most  instructive  features  connected  with  the  Caspian  is 
the  manner  in  which  it  h)ses  its  saline  constituents  by  discharging  into 
a  secondary  basin,  where  tlie  waters  mv.  still  more  highly  'joncentrated. 
On  its  eastern  shore  there  is  a  deep  bay  or  gulf  known  as  Karabogaza, 
which  is  nearly  shut  oft"  from  the  main  water-l)ody  by  intervening  sand 
bars,  and  receives  its  only  influx  through  an  opening  in  the  l)ar  about 
140  yards  broad  and  5  feet  deep.  The  water  escapes  from  Karabogaza 
solely  by  evaporation,  and  is  replaced  by  a  current  fi'om  the  Caspian 
which  has  been  estimated  by  Von  'Baer  to  carry  350,000  tons  of  salin(! 
matter  daily  from  the  sea  to  the  gulf.  The  waters  of  the  gulf  have 
reached  the  point  of  saturation  for  conunon  salt,  and  precipitation  is  tak- 
ing place.  These  peculiar  conditions  are  of  great  interesc,  not  oidy  in 
.showing  how  deposits  of  salt  may  accumulate,  Imt  also  in  illustrating 
the  manner  in  which  an  enclosed  lake  may  deposit  a  large  part  of  its 
foreign  matter  without  the  entire  Avater-body  becoming  highly  concen- 
trated. 


Saline  lakes  of  terrestrial  oriffiii.  —  The  existence  of  lakes  of  this 
class  depen<is  upon  a  combination  of  topographi",  and  climatic  conditions. 
The  basins  they  occupy  may  originate  in  almost  any  of  the  various  ways 
enumerated  in  Clmpter  I.  As  a  rule  the  lakes  of  this  class  in  Nortli 
America  occupy  depressions  formed  by  movements  in  the  earth's  crust 
Avhich  have  cut  off  large  areas  from  free  drainage  to  the  sea.  Such  en- 
closed basins,  hoAvever,  can  only  continue  in  regions  where  the  rainfall 
is  small,  for  the  reason  that  if  precipitation  were  in  excess  of  evaporation, 
they  would  become  filled  to  overflowing.  The  most  favorable  conditions 
for  the  founation  of  inland  saline  lakes  are  found  where  high  mountains 
discharge  their  di'ainage  into  basins  where  the  climate  is  arid.  A  region 
(jf  coiulenssvtion  of  atmospheric  vapors  and  a  region  of  concentration  by 
evaporation  are  thus  supplied,  which  supplement  each  other. 

The  saline  lakes  of  arid  regions  are  peculiarly  sensitive  to  climatic 
changes,  and  undergo  many  fluctuations.  When  the  mean  annual  influx 
and  the  mean  annual  los.s  by  evaporation  are  nearly  evenly  balanced,  lakes 
frequently  exist  only  during  the  rainy  season,  and  disappear  entirely  dur- 
ing the  hotter  portions  of  the  year,  leaving  broad,  smooth  mud  jjlains. 
Plains  of  this  character  are  a  characteristic  featui'e  of  the  arid  region  nl 
North  America,  and  are  known  in  Mexico  and  in  tlie  southwestern  pait 


Lakes  op  North  America. 


Pr.ATE  14. 


SALINE    AND   ALKALINE    LAKES    IN    THE    ARID    REGION. 


RELATION    OF    LAKKS    TO   CLIMATIC    CONDITIONS. 


71 


of  the  United  States  as  plai/ax.  It  is  convenient  to  adopt  this  name, 
and  call  the  temporary  water-bodies  to  which  phiyas  o^ve  their  oriifiii. 
pliiifn  lukra.  These  lakes  may  he  formed  l)v  a  single  shower  and  disai)- 
[)ear  in  a  few  honrs,  or  they  niay  endure  for  a  series  of  years  and  oidy  l)e 
evai)orated  to  dryness  during  seasons  of  exceptionally  low  rainfall  or  un- 
iisuall}'  active  <'vai)oration. 

When  enclosed  lakes  of  arid  regions  are  more  permanent,  they  fluctu- 
ate in  volume,  and  consequently  in  extent  and  in  density,  from  season  to 
season,  and  are  so  sensitive  to  climatic  changes  that  they  show  maikcd 
variations  when  ordinary  weather  observations,  taken  at  a  limited  nundier 
of  localities  in  their  neighborhood,  fail  to  indicate  analogous  changes  in 
atmos[)heric  conditions. 

The  terrestrial  saline  lakes  of  North  America  are  confined  to  the  arid 
region  of  Mexico  and  the  United  States,  although  small  })ools  of  alkaline 
water  do  occur  on  the  great  jdains  in  the  sul)-humid  region  cast  of  the 
Kocky  mountains  both  in  the  United  States  and  Canada.  The  saline 
lakes  of  the  United  States  are  conlined  almost  entirely  to  Utah  and 
Nevada  and  adjacent  [)ortions  of  the  Oreat  Basin.  The  distribution  of 
some  of  the  incn-e  important  lakes  here  referred  to,  is  indJcated  on  the 
accom})anying  map  forming  Plate  14.  The  chemical  composition  of  their 
v.aters  is  shown  in  the  table  on  page  72. 


Clieinical  pvocipitati's.  - —  The  deposition  of  mechanical  sediments,  as 
clay  and  sand,  in  lake  basins  has  already  Ijeen  referred  to.  This  takes 
place  in  all  lakes  without  special  reference  to  their  chemical  com])osition. 
When  lake  waters  become  concentrated  by  evaporation,  however,  the 
material  contributed  to  them  in  solution  may  l)e  precipitated,  and 
either  mingle  with  the  mechanical  sediments  fr  form  de])osits  of 
purely  chemical  origin.  Chemical  precipitates,  like  mechanical  sedi- 
ments, may  furnish  evidence  of  important  changes  in  a  lake's  history, 
and  are  also  frequently  of  great  interest  on  account  of  their  commercial 
value. 

As  already  seen,  enclosed  lakes  are  constantly  receiving  contributions 
from  streams,  springs,  and  rain,  but  do  not  overflow,  the  influx  being 
counterbalanced  by  evaporation.  This  assures  us  that  in  the  earlier  stages 
of  their  history,  at  least,  the  amount  of  saline  matter  held  in  solution  must 
increase  from  year  to  year  and  from  century  to  century.  This  process 
continuing,  a  time  is  eventually  reached  when  the  watei-s  will  be  saturated 
with  one  or  more  of  its  saline  constituents  and  precipitation  begin.    Watera 


7-2 


LAKES   OF    NOUTII    AMKUICA. 


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li()ltliii<,'  a  imiuluT  of  suits  in  soliitiDU,  when  slowly  cvaporiited,  do  not 
(lt'i>osit  thuni  in  a  lioino<,'tMU!()U.s  mass,  hut  in  sucuossive  layers  of  varyiiii; 
(•oiii[)osition.  As  tlic  order  in  wliieli  ditl'erent  salts  an;  dejjosited  varies 
with  the  eoniiiosition  of  the  waters,  it  is  safe  to  say  that  in  no  two  lakes 
is  the  snecH's-^ion  ot"  saline  deposits  formed  on  evaporation  a[)t  to  he  the 
same.  l)isre<^ardin^  for  the  [)resent  the  reaction  of  the  varions  salts  ii[»on 
each  other,  it  '  evident  that  in  the  evaporation  of  natural  waters  the 
order  in  which  the  contained  salts  will  he  i)recipitated  is  inversely  as  the 
Older  of  their  soluhility.  I'^or  exan'ple,  a  salt  which  re([uhes  a  l.irtfc 
amount  of  water  for  its  solution,  or,  in  other  words,  is  sjiarinjj^ly  soluide, 
will  reach  its  point  of  saturation  and  commence  to  crystallize  out  as 
evaporation  progresses,  previous  to  the  deposition  of  a  more  soluhle  salt. 
To  illustrate  :  it  has  hceu  found  that  calcium  carhonate  reciuires  ahout 
10,000  times  its  weii,dit  of  water,  saturated  with  carhon  dioxide,  for  its 
solution  ;  while  calcium  chloride  is  deli(][ueseent,  and  dissolves  in  ahout 
its  own  weijfht  of  water.  In  an  enclosed  lake  to  which  streams  and 
springs  are  hringing  these  two  salts  in  e(iual  quantities,  and  in  which 
evaporation  equals  or  exceeds  the  supply  of  fresh  water,  it  is  evident  that 
the  calcium  carhonate  wouhl  reach  its  [)()int  of  saturation  and  eoimnence 
to  sei>arate  long  hefore  the  waters  had  hecome  rich  in  calcium  cldoride. 
In  fact,  owing  to  the  deli(piescent  nature  of  the  cldoride,  natural  evapora- 
tion .seldom  proceeds  far  enough  to  cause  its  precipitation.  The  early 
deposition  of  calcium  carhonate,  when  natural  waters  are  concentrated  hy 
evaporation,  is  rendered  the  more  certain  for  the  reason  that  it  is  hy  far 
the  most  almndant  salt  found  in  surfi.ce  waters. 

The  fact  that  various  salts  are  deposited  in  a  I'egular  succession  when 
mineral  waters  are  evaporated,  is  of  great  service  in  separating  certain 
ones  in  a  jjure  state  hy  the  method  known  as  fractional  crystallization. 
In  evaporating  the  hrines  of  Syracuse,  New  York,  the  [»reci[»itation  of 
ferric  oxide  and  of  calcium  sul[)hate,  or  gyi)sum,  is  first  secured  hy  mod- 
erate concentration ;  the  hrine  is  then  conducted  to  lower  vat«  and  evapo- 
ration continued  until  the  sodium  chloride,  or  common  salt,  has  mostly 
crystallized  and  fallen  to  the  hottom  ;  the  mother-li(pior,  rich  in  magnesium 
and  calcium,  is  then  allowed  to  go  to  waste.  A  similar  process  frequently 
takes  place  in  nature,  but  the  salts  precipitated  collect  in  the  same  basin 
in  alternating  layei's. 

In  the  Soda  lakes  near  Ragtown,  Nevada,  a  double  carhonate  of  sodium 
and  calcium,  known  as  the  mineral  gaylussite,  forms  on  the  bottom,  owing 
to  natural  concentration.     When  the  waters  are  still  farther  evaporated, 


74 


LAKKS    OK    NOUTH    AMKItlC'A. 


Il{     1 

li'i 


sfxliiiin  siilpliatf  and  sodium  carlxtiirttf  are  jtrefipitated  previous  to  tlio 
I'lvstallizatioii  of  cominoii  salt. 

It  lias  ht'cu  round  on  font'eiitrutinj,'  sca-watci'  that  calcium  carbonate 
is  usually  the  first  c(»nstitucnt  to  be  jirccipitatcd.  This  salt  is  not  always 
found  when  tlic  waters  of  the  ocean  aic  analyzed,  hut  may  usually  he 
detected  in  sam|»les  taken  near  shore.  The  vast  quantity  delivered  to 
the  ocean  hy  rivers  is  soon  eliminated  hy  jilants  and  animals  and  secreted 
in  their  tissues. 

The  succession  of  chemical  iirecipitates  fnimcd  in  sea-water  has  heen 
described  by  M.  Dieulahiit'  as  follows: 

"  Fii-st  ii  very  weak  i)rc'cii)itation  occurs  of  carbonati!  of  lime  (calcium 
carbonate),  with  a  trace  of  strontium,  and  of  hy(bated  ses(iuioxide  of  iron, 
miiif^led  with  a  slight  proportion  of  mant^anese.  The  water  then  con- 
tiinu's  to  evaporate,  but  remains  perfectly  limpid,  without  forming-  any 
other  deposit  than  the  one  I  have  mentioned,  till  it  has  lost  80  per  cent 
of  its  oritjinal  volume.  It  then  bejifins  to  leave  an  abiuidant  ])recipitate  of 
perfectly  crystallized  sulphate  of  lime  with  two  e(pii\alents  of  water  or 
gypsum,  identical  in  Lj'eometrical  form  and  chemical  con-position  Avith 
that  of  the  jfypsum-beds.  This  deposit  continues  until  the  water  has 
lost  8  per  cent  more  of  its  orit^iual  volume  ;  then  all  }tiecii)itation  ceases 
till  2  per  cent  more  of  the  (uiyinal  (puuitity  of  witter  has  evaporated 
away.  Then  a  new  deposit  bej^ins,  not  of'  gypsum,  l)Ut  of  chloride  of 
sodium,  or  sea  salt.  .  .  .  The  deposition  of  piu'e  or  conunercial  salt  con- 
tinues till  the  volume  of  the  water  has  Ikmui  atjain  reduced  by  one-half, 
when  a  ijrecipitalion  of  sulphate  of  magnesium  beifins  to  take  i)lace  Avith 
it.  'J'his  continues,  the  two  salts  beinj,'  de[)osited  in  eijual  (piantities,  till 
only  3  per  cent  of  tlie  orijj^inal  (]uantity  of  water  is  left.  Finally,  Avhen 
the  water  has  been  concentrated  to  2  j)er  cent,  carnallite,  or  the  double 
chloride  of  jjotassium  and  mannesium,  is  deposited.  Spontaneous  evapo- 
ration cannot  i,n)  much  further.  The  residual  mother-water  will  not  dry 
up  at  the  ordinary  tempv.ature,  even  in  the  hottest  regions  of  the  ylolu'  ; 
its  chief  ccmstituent  is  chloride  of  magnesium.  A  body  of  sea-water 
evapcu'ated  naturally  Avill,  then,  leave  a  series  of  de})osits  in  Avhich  Ave 
Avill  find,  as  avc  diq-  down,  the  folloAving  minerals  in  order:  dclicpiescent 
salts,  including  chiefly  chloride  of  magnesium  ;  carnallite,  or  double  chlo- 
ride of  potassium  i'.nd  magnesimn ;  mixed  salts,  including  chloride  of 
sodium  and  sulphate  of  magnesia;  sea-salt,  mixed  Avith  sulphate  of  mag- 
nesia: pure  sea-salt:  ])Ui'e  gypsum;  Aveak  deposits  of  carbomite  of  lime 
Avith  sesquioxide  of  iion,  etc." 

1  ropular  Science  Moiitlily,  October,  1802. 


i;i:lati<)N  or  i,aki:s  to  climatu;  co.NDrnoNs. 


:5 


us  to  the 

Oarbonatc 
at  ahvay.s 
isni\lly  1m' 
livfii'cl  to 
I  sueieted 

•  has  Ik'cii 

e  (calcium 
(h'  of  iron, 
tlu'M    coii- 
riniii^'  any 
10  j)ci-  cent 
•cipitate  of 
il'  water  or 
sition  ^vith 
water  has 
tion  ceases 
evaporated 
•hlt»ri(k'  of 
il  salt  con- 
iV  one-half. 
)»laee  with 
ntitics,  till 
lially.  when 
the    (louhle 
|nns   cvaj)!)- 
ill   not  (h'v 
the  g-h)he  : 
st'a-water 
which  we 
litjueseent 
oul)le  chlo- 
;hh)ridc   of 
Ite  of  mag- 
te  of  lime 


Tn  the  natural  evaporation  of  water  in  enclosed  hasins  the  snceession 
will  seldom  l)e  as  icjrular  as  described  ai)ovc.  for  the  reason  that  the  process 
is  a|)t  to  he  interrupte(l  l)y  the  addition  of  fresh  supplies  of  watei',  and  the 
suceessioM  l)c;,fun  anew,  or  else  ehemieal  chan«."'s  initiate(l  which  will  vary 
the  results.  In  this  coniu'ction  it  is  to  lie  noted  also  that  chan^'cs  of  tem- 
perature, as  fi'om  sumnu'i   to  winter,  nmy  modify  the  successictn  of  salts 


(leoosi 


ted. 


The  sei)aration  of  sodium  sulphate,  potassium  chloride,  and  common 
salt  from  the  mother  li(pU)r  derived  fnun  the  concentration  of  sea-water, 
liy  alternate  evaporation  and  coolin<;\  is  the  jirinciple  (d"  Halard's  w(dl- 
known  ])rocess  largely  used  for  ohtainintf  salt  from  sea-watei'  in  the  south 
of  I'hudpc.  In  Mesel's  niodilication  of  this  }troct'ss,  a  low  tempeiature  is 
ol)taincd  artilicially.  When  sea-water  is  concentrated  until  its  specific 
gravity  is  1.24  (28°  of  IJcaume's  hydrometer)  it  deposits  ai>out  four-lift  lis 
of  the  conunon  salt  it  orij^inally  coutaiui'd  :  after  addinij  Id  per  cent  of 
sea-water  to  the  mother  litpior  remainiuf;,  it  is  passed  thiouu'li  a  refri^'cr- 
atiu}^  machine  and  its  temperature  lowered  t(»  —  18"  ('.  The  low  tempera- 
ture causes  double  decom|)ositiou  to  take  jtlace  lu'twicn  the  magnesium 
sulpliate  and  the  sodium  chloride,  sodium  sulphate  heinq-  deposited  and 
the  magnesium  chloride  remaining  in  solution.' 

A  process  similar  to  that  just  (leseril)ed  occvirs  in  nature,  as  is  shown 
hy  the  precii)itation  of  large  quantities  of  sodium  sulpliate  from  the  waters 
of  Great  Salt  hdce,  durinjr  cold  weather.  This  anticipation  of  llalai'd's 
]»rocess  is  noticed  in  advance  in  connection  with  other  features  of  (ireat 
Salt  lake. 

The  correspondence  hetwecu  the  succession  of  salts  formed  hy  the 
evaporation  of  sea-water,  and  the  succession  found  in  many  saline  dej)osits 
deeply  buried  in  the  earth's  ciust,  is  of  great  intcicst  and  no  doubt 
e\i)lains  the  genesis  of  souu'  natural  accunudatious  of  this  character.  It 
is  not  always  necessary,  Iiowcvit,  iii  seeking  an  expbmation  of  the  oiigin 
of  beds  of  common  salt,  gyj)sum,  etc.,  fouii<l  in  Icnticidar  masses  among- 
stratified  rocks,  to  assume  that  they  were  pn-ci[)itated  from  isolated  bodies 
of  sea-water.  On  the  contraiy,  the  study  of  saliiu'  lakes  has  shown  that 
similar  dc[)()sit.s  may  result  from  the  long  concentration  of  ordinary 
river  Avaters.  So  far  as  we  are  at  present  concerned,  however,  the 
process  in  either  case  is  the  same,  since  the  waters  of  the  ocean  itself 
<»we  their  salinity  in  a  great  degree  to  the  concentration  of  the  waters 
of  streams. 

1  Report  of  .luries  :  International  Kxhibition,  18(i2,  Class  II,  pp.  48-54. 


7(; 


liAKKS    (»!•     NOIITII    AMKKK.'A. 


Kiiowiiijf  tlic  MiU't't'SHion  in  which  viiiiims  suits  arc  t'liminutcd  when 
Wiitfis  luv  coiicenuated  by  tiviiixuation,  it  hccoiiu's  possiiih'  to  (h'tcniiiiif 
ill  sonic  instam-cH,  tidiii  the  succcssiuii  of  salts  discovered  in  a  desiccated 
lake  liasin,  what  chaii^'cs  occurrcil  ii:  the  life  of  the  lake  from  which  they 
were  precipitatt'd.  In  the  case  of  Lake  Lahontan,  descrihed  in  advance, 
this  method  has  led  to  interesting^  ccniclnsicns.  In  a  similar  way,  the 
chemical  comp(»sition  of  a  lake  enahles  one  to  draw  important  inferences 
in  reference  to  its  past  history.  A  lake  in  which  the  rarer  elements  found 
in  tributary  streams  are  abundant,  must  have  underjnfone  a  long  [)eriod  of 
coiiceiitriition,  and  formed  deposits  of  the  more  common  and  less  readily 
solultlc  salts.  If  a  lake  occupyiiifjf  an  inclosed  basin  which  has  never 
overflowed,  contains  but  a  small  percentage  of  the  salts  most  common  in 
(le  intiowiiig  streams,  it  is  evident  that  there  must  bo  some  process  by 
which  such  salts  may  be  eliminated  without  being  flooded  out.  Search 
should  then  be  made  for  this  new  princii)le. 

When  hike  waters  are  concent ni  ted  the  first  precii)itates  formed,  as 
already  seen,  are  ferric  oxide  and  calcium  carbonate.  'I'hese  substances  an; 
retained  in  solution  mainly  by  reason  of  the  iiresence  of  carbon  dioxide, 
caibonic  acid,  in  the  water.  As  evaporation  progresses  and  also  when  the 
waters  are  agitated,  as  in  the  breaking  of  waves  on  shore,  the  carbon 
dioxide  escajjcs  and  the  iron  and  lime  previously  held  in  solution  arc 
))recii)itated.  The  iron  while  in  solution  is  in  chemical  combination  with 
the  carbon  dioxide,  forming  ferric  carbonate,  when  it  loses  its  carbonic 
acitl  it  is  precipitate<l  as  ferric  oxide.  The  lime  in  solution  is  believed 
to  be  in  the  form  of  the  bicarbonate,  and  on  losing  carbon  dioxide  is  pre- 
cii»itated  as  the  carbonate. 

It  is  a  fact  of  geological  interest  that  iron  and  lime  held  in  solution 
may  also  be  precipitated  on  account  of  the  withdrawal  of  carbon  dioxide 
through  the  agency  of  plant  life.  Low  forms  of  vegetation,  known  as 
algae,  thrive  in  the  waters  of  both  fresh  and  saline  lakes  and  even  in  hot 
springs  wheie  the  temperatiu-e  approximates  to 'that  of  boiling  water. 
Through  the  vital  action  of  this  vegetation  carbon  dioxide  is  removal 
from  water  in  much  tlie  same  manner  that  higher  forms  of  i)lant  life 
eliminate  it  from  the  atmosi)here.  Carbon  is  assimilated  and  oxygen 
liberated.  Iron  on  parting  with  its  carbon  dioxide  unites  with  the  liber- 
ated oxygen  and  is  precipitated  as  ferric  oxide. 

It  has  recently  been  shown  that  large  deposits  of  both  calcareous  tufa 
and  silicious  sinter  are  deiiosited  through  the  agency  of  fresh  water  algae 
from  the  waters  of  hot  springs  in  the   Yellowstone  I'ark.     The  silicia 


I!KI,ATI()N    Ol'    LAKKS    TO   CLIMATIC    CONlJlflONS. 


77 


ill  siicli  iiistiuicos  H«'i'ins  to  !«'  st'ciotcd  by  tlic  |>l;iiits  us  ii  j)art  ol"  tlii-ir 
vitiil  t'uiictioii.  Iiiit  tlu'  process  is  not  woll  iimU'istood.' 

'V\h'  ori^jin  of  oiilitic  siind,  consist iiiLf  of  little  spheres  tonnud  of 
coiietiitiie  eo;its  of  eidciuiii  ciirhoimte,  iiloii^  the  shores  of  (iicat  Salt  lake, 
has  hoeii  referred  to  an  aiialoLfoiis  proeess.- 

Coial-like  ^'rowlhs  (»f  ealeaieoiis  tufa  in  some  of  the  stronj,'ly  alkaline 
lakes  of  the  (irout  llasin  are  also  thoiighl  to  owe  ihuir  origin  to  iho 
agency  of  low  forms  of  phint  life/* 

An  important  feature  in  this  function  of  sulwupioous  idunts,  is  that 
calcium  carbonate  may  he  [irecii)itated  from  waters  that  aru  far  below  tho 
|)oint  of  saturation.  In  some  instances  precipitation  is  known  to  occur  in 
this  manner  from  water  in  which  chemical  ti'sts  fail  to  rcvi-al  moiv  {\:m\  a 
trace  of  calcium. 

Feme  oxide  is  not  known  to  be  an  important  dcjiosit  in  any  of  tho 
lakes  of  North  America,  although  found  in  abundance  in  many  swamps. 
Ill  Sweden,  however,  its  precipitation  from  the  water  of  fresh  lakes  is  so 
abundant  that  it  is  of  conunercial  value.  The  iron  is  carried  into  the 
lakes  by  streams,  as  Ji  carbonate,  and  is  [irecipilated  on  account  of  the  loss 
of  carbon  (hoxide,  in  part  at  least,  thidugh  the  agency  of  low  forms  of 
vegetative  life.  In  some  instances  diatoms  aie  thought  to  play  an  im- 
portant part  in  secreting  the  iron. 

With  this  brief  sketch  of  the  manner  in  which  i)reeii)itates  may  be 
foi'med  in  lakes,  let  us  turn  to  actual  eases  where  the  process  is  in 
operation.  Of  the  considerable  number  of  saline  lakes  of  North  America 
that  have  been  studied,  two  arc  here  selected  as  types.  These  are  Great 
Salt  lake,   Utah,  and  Mono  lake,  California. 

<iiroat  Salt  lake,  I'tali.  —  This  celebrated  sea  is  situated  in  the  eastern 
portion  of  the  Great  Basin  near  the  west  base  of  the  Wasatch  mountains. 
Its  hydrographic  basin  has  an  area  of  54.000  s(pmre  miles,  and  is  divided 
into  two  strongly  contrasted  portions.  The  eastern  part  is  moiuitainous 
and  contains  ])eaks  12,000  feet  in  height  above  the  sea,  or  8000  feet  above 
the  lake.  The  western  portion  is  composed  of  desert  valleys  but  little 
elevated  above  the  lake  surface,  and  separated  l)y  narrow,  a])rui)t,  desert 
langes  rising  from  one  to  two  thousand  feet  or  more  above  adjacent  valleys. 

1  W.  II.  Weed.  "The  Formation  of  Travortine  and  Sillciou.s  Sinter  by  the  Vegetation 
of  Hot  Springs,"  0th  Annual  Report,  U.  S.  Geological  Survey,  1887-88,  pp.  (Jl.3-076. 

'■^  A.  Uothplitz.    "On  the  Formation  of  Oiilite.''  American  (Jeologist,  vol.  10,  pp.  270-282. 

^  I.  C.  Kussell.  "A  Keconnoissauce  in  Central  Wiishiug'.on,"  Bulletin  No.  108,  U.  S. 
Geological  Survey,  pp.  04-06. 


u.i  !H 


78 


LAKES    OF    N<J11TH    AMKItlCA. 


il 

III 
I 


The  elevation  of  tlr;  lake's  suiface  varies  somewliitt  during  different 
years  and  from  season  to  season,  owing  to  diniatie  cluinges,  and  to  the 
fact  that  the  flow  of  the  streams  sujjplying  it  is  interfered  with  for  piii- 
|)oses  of  irrigation.  Surveys  made  May  Ui,  1883,  gavy  a  surface  level  of 
4218  feet  above  the  sea. 

Its  area  is  also  changeable.  On  a  ma[)  made  from  surveys  under  the 
direction  of  Lieut.  Stanslmry,  in  I8o0,  it  is  repiesented  as  having  an  area 
of  about  1750  s(|uare  luiles.  A  second  ma}),  made  in  connection  with  th(> 
Fortieth  Parallel  survey,  in  charge  of  Clarence  King,  in  1809,  shows  an 
area  of  217<>  si^uare  miles  ;  the  increase  m  I'J  years  l)eing  420  square 
miles,  or  24  per  cent.  Its  outlines  when  these  surveys  were  made  aiv 
shown  in  Plate  15. 

At  its  highest  observed  stage  in  18G0,  it  had  a  maximum  depth  of  4'J 
feet,  and  an  average  depth  of  approximately  19  feet.  In  1850,  the  maxi- 
mum de[)th  was  30  feet,  and  the  average  .ibout  13  feet.  Since  1875, 
careful  records  of  the  fluctuations  of  level  liavc  been  made  and  Ijotli 
annual  and  secular  changes  noted. ^  The  annual  high-water  stage  occurs 
in  June,  and  is  due  to  the  melting  of  the  snow  on  the  Wasatch  and 
Uintah  mountains.  The  fluctuations  embracing  a  series  of  years  have 
not  been  found  to  be  regular  in  their  periods  and  are  not  coincident  with 
observed  climatic  changes. 

The  sliores  of  Great  Salt  lake  are  h)w  exce[)t  where  a  mountain  uplift 
j)rojects  into  it  from  the  north,  forming  a  rocky  promontory,  and  for  a 
sliort  distance  on  its  south  shore  where  it  touches  the  northern  end  (>f  the 
Oijuirrh  mountains.  Its  surface  is  broken  by  several  islands  of  whicli 
two  are  short  mountain  ranges  of  tlie  type  so  characteristic  of  the  (in  ;it 
Hasin.  These  rise  more  than  a  thousand  feet  above  its  surface  and  ;iiv 
rugged  and  precipitous.  They  stand  like  Nilometers  in  the  salin.;  .vaters. 
and  on  their  sides  are  many  horizontal  lines  marking  former  levels  of  the 
lake's  surface.  Tlie  highest  of  these  scorings  is  about  1000  feet  above 
the  present  water  surface. 

The  scenery  about  this  great  lake  of  the  Mormon  land  and  in  the  encir- 
cling mountains  is  unusually  fine,  in  spite  of  the  aridity  and  the  generally 
scant  vegetation  of  the  region.  The  sensation  of  great  breadth  that  tlie 
lake  insi)ires,  together  with  the  picturesque  islands  diversifying  lbs  sur- 
face, and  the  utter  desolation  of  its  shores,  give  it  a  hohl  on  the  fancy,  ami 
wakens  one's  sense  of  the  artistically  beautiful  in  a  way  tliat  is  unrivaleil 

'  The  rcciinls  (if  tliesc  clinnjit's  up  to  IS'.tO.  tou;etlit'r  with  ii  (lisciissinii  of  tlieir  .sijiiiiticanci' 
is  .yivfu  by  G.  K.  CiilbiTt,  in  Muuo<;mpli  Nu.  1,  U.  S.  Geological  Survi'j-. 


.>  ''^X 


Lari:s  of  Xonrn  AMKiiir.\. 


Pi.ATr;  Vi. 


iBRfOHAM  CITY 


CdREAT    SALT    LAKE,    UTAH.    (AFTER  GILBERT,) 


rsiguitioiiucc 


m: 


ii. 


RELATION    OF   LAKES   Tt-    CLLMATIC    CONDITIONS. 


70 


1))'  any  other  lake  of  the  Arid  region.  Tlie  iinusuiilly  clear  air  of  Utah, 
especially  after  the  winter  rains,  renders  distant  niountains  remarkably 
shar[)  and  distinct,  jjarticularly  when  the  sun  is  low  in  the  sky  and  a 
strong  sidelight  hiings  the  sharp  serrate  crests  into  bold  relief  and  reveals 
a  richness  of  sculpturing  that  was  before  unseen.  At  such  time  the  colors 
on  the  broad  deserts,  and  amid  the  pur[)l(!  hills  and  mountains,  are  more 
wonderful  than  artists  have  ever  jtainted,  and  exceed  anything  of  the 
kind  witnessed  by  the  dweller  of  regions  where  the  atmosphere  is  moist 
and  the  native  tints  of  the  rock  concealed  bv  vegetation.  The  hills 
of  New  England  when  arrayed  in  all  the  gorgeous  panoply  of  autumnal 
foliage  are  not  more  striking  than  the  desert  ranges  of  Utah  when 
ablaze  with  the  reflected  glories  of  the  sunset  sky.  The  rich,  native 
colors  of  the  naked  locks  are  then  kindled  into  glowing  lires,  and  each 
canon  and  rocky  gorge  is  filled  with  liquid  purple,  l)eside  whi(;h  even  the 
Imperial  dyes  would  be  dull  and  lusterless.  At  such  times  the  glories  of 
the  hills  are  mirrored  in  the  dense  water  of  the  lake  :  their  duplicate 
forms  appearing  in  sharp  relief  on  the  paler  tints  of  the  reflected  sky. 
As  the  sun  sinks  behind  the  far-off  mountains,  range  after  range  fades 
through  innumerable  shades  oi!  piu'ple  and  violet  until  only  theii-  highest 
battlements  catch  the  fading  glory.  The  lingering  twilight  brings  softer 
and  more  mysterious  beauties.  IJanges  and  peaks  that  we"e  concealed  by 
the  glare  of  the  noon-day  sun,  start  into  life.  Ft)rms  that  were  before 
unnoticed,  people  the  distant  plain,  like  a  shadowy  encampment.  At  last 
each  I'emote  mountain  crest  appears  .as  a  delicate  silhouette,  in  which  all 
details  are  lost,  drawn  in  the  softest  of  violet  tints  on  the  fading  yellow 
of  the  sky. 

To  one  who  only  beholds  the  desert  land  bordei-ing  Great  Salt  lak(i  in 
the  full  glare  of  the  unclouded  sununer  sun,  when  the  peculiar  desert 
haze  shrouds  the  landscape  and  the  strange  mirage  distorts  the  outline  of 
the  hills,  the  scenery  will  no  doubt  be  uninteresting  and  perhaps  even 
re[)ellent.  But  let  him  wait  until  the  cool  bresith  from  tlie  mountains 
steals  out  on  the  plain  and  the  light  becomes  less  iatense,  and  a  t-ansfor- 
mation  will  be  witnessed  that  will  fill  his  heart  with  wonder. 

The  saline  and  alkaline  shores  of  Great  Salt  lake  are  either  naked 
mud  plains,  frecpiently  white  with  drifting  salts,  or  scantily  clothed  with 
desert  shrubs.  The  absence  of  conspicuou.^  flowers  is  freipiently  relieved 
by  broad  areas  covered  witii  a  peculiar  plant,  known  as  Snliconiia^  whi(;h 
flourishes  by  the  side  of  this  Dead  Sea  of  the  West,  where  all  other  vege- 
tation perishes.     The  Salieornia  grows   in  fleshy  stems,  without  leaves, 


r 


80 


LAKES   OF   NORTH    AMEltlCA. 


■  "^       If 

■a !  j 
'  j 

1%. 


and  look"*  not  unlike  hranehing  coral.  It  is  of  many  shades  oi;  red,  pink, 
and  yellow,  thus  still  further  increasing  its  resenihlance  to  groves  of  li\  ing 
coial.  The  white,  alkaline  desert  is  fre(|nently  tinted  by  this  strange 
plant  until  it  glows  like  a  lield  oi  iMpine  flowers.  There  are  many  other 
interesting  features  to  he  noted  hy  the  visitor  to  the  great  desert-lake  of 
Utah,  but  its  i)hysical  and  chemical  history  claims  our  attention  at  this 
time  rather  than  its  artistic  setting. 

The  streams  Hewing  to  the  lake  rise  in  the  high  mountains  to  the  east 
and  are  clear  and  limpid,  and  of  such  purity  that  only  chemical  tests 
reveal  the  presence  of  the  mineral  matte;  they  have  dissolved  from  tlic 
rocks  and  soils.  Several  of  these  streams  are  truly  rivers  in  volume,  as 
well  as  in  name,  and  send  a  naver-ceasing  flood  to  the  lake.  Their  com- 
bined volumes  average  throughout  the  year  about  10,000  cubic  feet  per 
second.^ 

There  are  a  number  of  fissure  springs  a1)0Ut  the  lake,  or  rising  beneath 
its  surface.  In  some  instances  these  are  hot  and  contain  more  saline 
matter  in  solution  than  is  usually  found  in  surface  streams.  These  con- 
tribute a  considerable  quantity  of  the  saline  matter  found  in  the  waters  of 
the  lake,  but  it  is  Ijelieved  that  the  amount  thus  derived  is  less  than  that 
furnished  l)y  streams  from  the  mountains.  This  conclusion  rests  on 
incomplete  data,  however,  as  neither  the  volume  nor  the  composition  of  all 
the  springs  is  known.  None  of  the  springs  supplying  the  lake,  with  a 
single  known  exception,  of  small  volumes,  are  markedly  saline  The  salts 
they  contain  are  ac(piired  largely  during  the  upward  jjassage  of  the  water 
tlu'ough  the  i-ediment  of  former  lakes  and  their  influence  on  the  chemistry 
of  the  present  lake  is  more  im[)ortant  than  in  the  case  of  any  other  lake  in 
the  same  region.  It  is  safe  to  conclude,  however,  that  the  combined 
volumes  of  the  streams  and  springs  now  tributary  to  the  lake,  if  not  con- 
centrated by  evaporation,  would  form  a  A\ater  body  in  which  no  trace  of 
saline  matter  would  be  apparent  to  the  taste. 

Analyses  of  the  waters  of  Bear  river,  of  Utah  lake,  from  which  the 
Jordan  flows,  and  of  City  creek,  one  of  the  numerous  streams  f}-om 
the  Avest  slope  of  the  Wasatcl;  mountains,  give  an  average  of  about 
0.2446  part  per  thousand  of  mineral  matter  in  solution.  This  may  be 
taken  as  the  average  composition  of  the  surface  stream  flowing  to  the 
lake.  As  will  be  noticed  on  referring  to  the  average  conij)osition  of 
normal  rivers  previously  given,  the  mineral  matter  in  these  streams  is 
nearly  double  the  amount  carried  in  the  same  volume  of  water  by  streams 

1  G.  K.  Gilbert.     "  Lands  of  the  Arid  Region,"  Waaliington,  1879,  p.  72. 


KKLATION    OF    LAIvKS    TO    CLIMATIC    CONDITIONS. 


81 


id,  pink, 
:)f  lisiiiii: 
stnuige 
iiy  other 
t-lakt!  of 
I  lit  this 

I  the  east 
ical  tests 
from  the 
iibuiie,  as 
heir  eoni- 
c  feet  per 

g  beneath 
ore  saline 
iliese  fon- 
waters  of 
than  that 
rests  on 
tion  of  all 
e,   with  a 
inie  salts 
the  Avater 
chemistry 
cr  lake  in 
mhinetl 


eo 


f  not  eon- 


lio  trace  o 


f 


Iwhieh  the 
from 


jams 


of  ahont 
Ins  may  l)e 
Intr  to  thti 


f 


losition  o 


streams  is 


'.y 


streams 


in  more  hnmid  re_i,'ions.     This  is  due,  in  a  measure,  to  the  active  evapora- 
tion that  takes  ])lae('  fiom  them  a!id  from  the  lakes  on  their  courses. 

The  waters  of  (heat  Salt  lake  have  been  analyzed  at  six  different 
times.  T..0  lesults  of  these  several  analyses  are  widely  at  variance  on 
account  of  fluctuations  in  the  volume  of  the  lake.  The  dates  at  which  the 
various  samples  analyzed  wei'e  collected  and  the  total  solids  found  in  1000 
parts  of  water  are  here  given  :  ' 

Datt!      .     .     .     1S.')()    siiiimuT  LSd!)     Auj;-.  isTo     Dec.  ISS.")     An-.  ISS!)      Ang.  Ls!)l>  ^s 

1.1 11  l.l(i-J  l.lL'li 

lls.L'  l:!(;.7  KI7.-J 


Specific  <;r;>''f   1.170 
Parts  in  Kmh.       __!.■_' 


1.157 

111.")..") 


l.ir)({ 

•JO').l 


Since  the  accompanying  table  of  analysis  of  hike  waters  was  com[)iled, 
my  attention  has  been  directed  to  the  analysis  given  below,  which  in 
several  ways  is  the  most  com[)let(}  and  satisfactory  that  has  been  pul)- 
lished. 

Analvsls  of  a  samplk  ok  tiik   Watku  ok  Cukat  Salt  Lakk.     Collkcted 

Ai(UST  !),  isu-2:^ 

1>Y  E.  Wali-ku. 
[Expresst'il  in  OrMiiis  in  :i  I.itiT.     Spfcitie  (iiavity,  1.1.5fi.] 


Kl.lCMKST.S 

AXI)  Uadrals. 

PKOIIAIII.E  CoMllINATInX. 

Xa 

K 

r.i 

7">.S-i.") 

:].!»•_>,-) 

.     .                .       ().()"M 

XaCl 

K  ,s()             

llfi.SliO 
s.7.")(> 

l.i...SO^ 

M^Cb 

M'4Sf), 

(aSO, 

FeJ),  and  AljC),, 

SiO 

o.Hlil 

l.-).()41 

.j.:.'l(; 

S.L'tO 
(l.iKIl 
(I.OIS 

.M- 

Ca    .     .     .     . 

4..S14 

•)  |->  J 

t'l 

^<>j. 

()  ill  sulphates    . 

Fe.,(),,  and  Al,(),, 

SiO.^      .... 

lU ),,(),,.     .     .     . 

Hi- 3      .... 

.....   1-JS.J7.S 

l-2.:y22 

'2Mn 

(I.OOl 

O.OIS 

Trace 

.     .     .     .  Faint  trace 

.Surplus  SO.j 

Total      ..... 
Total  solids  hy  evajioration 
"         "     [duplicate]    .     .     . 

(i.().")l 

•j:}s.l-J 
2:i7.0'2.') 

The  average  comi)osition  of  the  ccnnbined  spring  and  stream  waters 
tributary  to  the  lake  cannot  l>e  stated  with  accuracy,  but.  judging  from 

'  A  compilation  of  various  analyses  of  the  water  of  Great  Salt  Lake  and  a  di-scussion  con- 
cern inst  tlieni,  is  ,i,dven  by  (i.  K.  Gilbert,  ^lonop-apli  No.  1,  l'.  S.  Geological  Survey. 
•^  SchooU>f  Mines  [Columbia  College]  (Quarterly,  vol.  14,  1H',I2,  p.  58. 
*  A  later  detcriaination  showed  about  0.01  gram  of  Hr.  in  a  liter. 


I 

■fl* 


9*4  LAKES    OF    NORTH    AMKIUCA. 

sucli  observations  as  bear  on  tlie  (juestioii,  it  seems  safi;  to  assume  tliat 
tlieir  min^^ed  waters  would  coutaiu  less  tliau  doulile  llie  ])ereeiitage  of 
saline  matter  found  in  the  surfaee  streams.  The  assum[)tion  that  t!ie 
combined  sjjring  and  stream  waters  woiUd  contain  alxmt  (K'-\  part  in  a 
thousand,  or  three  one-hundredths  of  one  per  cent  of  total  solids  in  solu- 
tion, seems  as  close  an  ai)[)roximatiou  as  can  now  be  reached. 

The  waters  of  the  lake  durinij  recent  low  stages  have  become  nearly 
saturated  with  sodium  chloride  and  sodium  sulphate,  and  under  certain 
conditions  these  salts  are  precipitated.  The  point  of  saturation  for 
calcium  carbonate  is  passed,  and  this  salt  is  precipitated  [)robaljly  as 
ra[)idly  as  it  h  received.  The  waters  are  not  rich  in  the  (;omi)ounds  of 
bromine,  boron,  lithium,  and  iodine,  which  frequently  occur  in  "  mothei- 
liquors,"  remaining  when  the  more  connnon  salts  have  been  eliminated  by 
long  concentration,  and  hence  indicating  the  old  age  of  a  lake  containing 
them.  The  recent  analysis  by  Waller,  however,  shows  these  rarer  elements 
to  be  present  in  somewhat  larger  (quantities  than  was  previously  su[)iK)scd. 

The  length  of  time  that  would  be  required  to  charge  Great  Salt  lake 
with  the  common  salt  it  contains,  under  the  present  conditions,  is  estimated 
by  Mr.  Gilbert  at  about  25,000  years.  i. 

The  (quantity  of  sodium  chloride,  or  connnon  salt,  held  in  the  water 
of  the  lake  is  estimated  at  400  million  tons,  and  the  sodium  sulphate  at 
30  million  tons.  These  iigures  indicate  the  commercial  importance  of 
this  great  leservoir  of  brine.  The  separation  of  the  common  salt  has 
alieady  led  to  a  consideral)le  industry,  as  from  20  to  40  thousand  tons 
have  been  gathered  yearly  for  a  considerable  period.  Tlie  most  extended 
and  best  conducted  of  these  operations  are  carried  on  by  the  Inland  Salt 
Company  at  the  southern  end  of  the  lake.  Evaporating  vats  covering 
more  than  one  thousand  acres  have  been  constructed,  and  are  supplied  by 
pumps  which  deliver  14,000  gallons  of  lake  water  per  minute.  Pumping 
is  continued  through  May,  June  and  July,  and  the  salt  is  ready  for  gather- 
ing in  August.  Dui'ing  midsummei'  the  amount  of  water  eva[)orated  is 
8,400,000  gallons  daily.  The  yield  of  salt  is  at  the  rate  of  150  tons  per 
inch  of  water  per  acre.  An  average  season's  yield  is  a  layer  of  salt  about 
seven  inches  thick,  which  would  be  i)recipitated  from  forty-nine  inches  of 
water.  The  facilities  for  this  industry  may  be  judged  by  the  fact  that 
coai-se  salt  packed  on  cars  ready  for  shipping,  is  sold  at  the  works  for  one 
dollar  per  ton.  The  mother-liquor  is  allowed  to  go  to  waste,  but  it  is  to 
be  expected  that  sodium  sulphate  and  other  salts  contained  in  it  will  be 
utilized  in  the  near  future. 


KELATION    OF    I  VKE8   TO    CLIMATIC    CONDITIONS. 


83 


Along  tlie  niiugi'-i  of  (rreat  Salt  lake,  where  the  water  is  only  a  few 
inches  deep,  it  hecomes  so  concentrated  by  evajmration  that  common  salt 
crystallizes  and  forms  a  hrilliant  white  hiyer  on  the  l)ottom.  In  fordin<^ 
an  arm  of  tlie  lake  about  a  mile  l)road,  in  order  to  reach  Staiisbury  island, 
the  writer,  in  1880,  found  a  crust  of  salt  formint^  a  fflisteuinf^  pavement 
strong  enough  to  support  a  horse  and  rider,  but  occasionally  it  would 
give  way  and  lead  to  uncomfortable  tlounderings  in  the  black  nuul 
beneath. 

The  solubility  of  sodium  sulphate  is  controlled  largely  by  tempera- 
ture. In  Great  Salt  lake  in  summer  it  is  all  dissolved  and  the  watei-s  are 
clear,  but  as  cold  weather  ap])roaches  it  separates  and  renders  the  waters 
opalescent  and  somewhat  milky  in  (;olor.  In  the  dc]»th  of  winter,  when 
the  temperature  falls  below  zero  of  the  Fahrenheit  scale,  as  it  does  at 
times  for  days  together,  this  salt  seitarates  in  great  abundance  and  is 
thrown  ashore  by  the  waves  in  hundreds  of  tons,  forming  a  slush-like 
mass  on  the  beach  looking  like  soft  snow.  On  such  occasions  it  can  be 
gathered  in  practically  unlimited  quantities,  l^ut  is  soon  re-dissolved  when 
the  temperature  rises. 

The  brine  of  the  lake  is  so  concentrated  that  fish  cannot  live  in  it,  but 
it  furnishes  a  congenial  home  for  small  crustaceans  known  as  brine  shiimi)s 
(Artemia)  and  for  the  larvae  of  dipterous  insects.  These  are  abundant 
at  certain  seasons,  but  not  in  such  vast  numbers  as  in  some  of  the  more 
alkaline  lakes  on  the  west  side  of  the  Great  Basin.  It  has  l)een  stated 
that  the  vast  numbers  of  crustaceans  and  of  larvae  in  these  waters  are  due 
to  the  fact  that  there  are  no  fishes  or  other  animals  in  the  lakes  that 
could  prey  upon  them  ;  a(iuatic  birds,  however,  feed  upon  them  in  great 
numbers,  but  still  the}'  swarm  in  countless  myriads.  Their  food  seems 
to  be  minute  algae  of  which  several  species  have  been  described. 

As  shown  by  the  an.dysis  given  above,  the  principal  salt  in  Great  Salt 
L.ake  is  sodium  cidoride.  In  the  second  example  of  the  saline  lakes 
described  below  the  characteristic  ingredients  are  sodium  ijarbonate  and 
sodium  sulphate.  (Jreat  Salt  lake  may  be  said  to  be  a  mit  lake  in 
distinction  from  a  number  of  water  bodies  situated  especially  on  the 
w<  st  side  of  the  (ireat  Basin,  which  may  with  propriety  be  designated 
as  alkaline  lakes. 


Mono  lake,  California.  —  This  lake,  selected  as  the  type  of  a  series 
of  strongly  alkaline  Avater-bodies  in  the  desert  basins  of  the  Arid  region, 
is  situated  in  south-eastern  California,  within  a  few  miles  of  the  Nevada 


84 


LAKKS    OF    NoltTH    AMKUICA. 


lioiUKliiry.  It  lies  at  tlie  imnuMliiitt'  fiistciii  biise  of  tlu'  Sierra  Neviulu, 
from  wliieh  it  receives  pnietically  all  of  its  water  supply,  and  occiipies 
one  of  the  minor  basins  eomposinj^'  the  yivat  area  of  interior  (Irainaj^e 
known  as  the  Great  Basin.  Its  position  on  the  wt-st  side  of  tluf  (ireat 
IJasiii  and  at  the  base  of  tlie  yicat  fauU  s(ar[)  forniino-  the  [Mccipitous 
eastern  sloi)e  of  the  Sierra  Nevada,  is  similar  to  the  situation  of  (ireat 
Salt  Lake  on  the  east  side  of  the  same  broad  desert  area,  and  at  tlie  west 
]>ase  of  the  mat-nit  lee  nt  fault  scar[)  forming-  tin;  abrupt  western  face  of  the 
Wasatch  ran^e.  Mono  lidve,  like  many  other  enclosed  water  liodies  of 
the  Arid  rcj^ion,  is  of  ancient  lineaLje,  as  is  shown  by  numerous  beach 
lines,  carved  by  former  water  bodies,  on  the  inner  slopes  of  this  valley. 
The  hit^hest  of  these  lines  is  from  ('>70  to  080  feet  above  the  present  water 
surface. 

The  hydrographic  basin  of  Mono  lake  has  an  area  of  nearly  7000 
square  miles,  and.  as  in  the  ease  of  the  regitm  draining  to  (treat  Salt  lake, 
is  divided  into  two  strongly  contrasted  portions.  The  southwestern  part 
is  numntainous  and  rugged,  and  bristles  with  serrate  peaks  that  rise  over 
six  thousand  feet  above  the  lake's  surface.  On  the  mountains  tlie  snow- 
fall is  abundant,  and  several  small  glaciei's  exist  in  the  higher  valleys. 
'J^he  eastern  i)ortion  of  the  drainage  l)asin  is  comparatively  low.  and  is 
arid  and  desert-like  in  character.  Little  rain  falls  on  this  portion  of  the 
basin,  and  there  are  no  perennial  streams.  Only  occasionally  is  tlicre 
sulKcient  precipitation  to  produce  a  surface  drainage,  and  normally  the 
rain  w'ater  and  the  water  produced  from  the  melting  of  the  light  winter 
snows,  is  al)soi'bed  at  once  by  the  thirsty  soil  or  returned  to  tlie  atmosphere 
by  evaporation.  / 

To  gain  a  eomi)rchensive  idea  of  the  geograi)hy  of  the  interesting 
region  about  ]Mono  lake,  one  shimld  climb  some  commanding  summit  on 
the  High  Sierras,  on  its  southwestern  bolder,  and  study  the  inagnilicont 
])anorama  s])rea(l  out  at  his  feet.  Let  the  reader  come  with  me-  to  the 
siunmit  of  Mt.  Dana,  named  in  honor  of  the  venerable  J.  D.  Dana,  one 
of  the  most  prominent  peaks  overlooking  Mono  lake,  and  I  Avill  endeavor 
to  i)oint  out  some  of  the  more  interesting  features  of  the  land  we  are 
studying.  ;       .     ■    . 

The  summit  we  have  reached  is  nearly  13,000  feet  above  the  sea.  The 
only  neighboring  mount'..ins  exceeding  it  in  altitude  are  Mt.  Lyell  and 
Mt.  Hitter,  which  rise  with  dazzling  w-hiteness  against  the  southern  sky. 
From  our  stiition  the  entire  Mono  basin  is  in  view,  and  much  of  its  his- 
tory can  be  read  as  from  a  printed  page.     We  are  standing  on  one  of  the 


t 


DELATION    Ui-'   LAKKS   TO    CLIMATIC    CUNlUTlUN.S. 


85 


liijifhest  points  on  tlu!  rim  of  a  sliar[)ly  dt'liiu'd  liy(lr(»j,'iiii>lii('  Imsiii.  Tlio 
(Iniiiiiij^i!  from  nil  directions  tcMids  towiinls  tin;  ct'iitiu'  and  forms  a  lako 
from  wliich  tlu'  waters  I'scape  oidy  l>y  evaporation.  Wc  ean  trace  neaiiy 
tlie  entire  honndary  line  of  tlie  i)asin,  for  tlie  reason  that  tlie  slopes  are  so 
plainly  marked  and  the  crest  lines  so  sliar[)ly  drawn,  that  there  is  no  doul)t 
us  to  the  direction  that  surfaco  water  would  take.  The  coui-ses  (»f  the 
swift,  lu'ii^ht  stream  descendinj]f  the  mountain  can  Ix;  foUowed  from  their 
sources  in  meltiufj  snow-lields,  down  through  deep  cafions  to  where  they 
enter  the  lake.  On  the  desert  side  of  the  basin,  however,  there  are  no 
streams,  and  hut  indelinite  traces  of  the  (hy  beds  of  former  water-courses. 
There  is  no  notch  in  tlu?  rim  of  the  basin  to  suf^tfcst  a  former  outU't.  The 
only  possible  point  of  discliarjj^i!  for  the  watei-s  when  the  ancient  beaches 
scoring  the  inner  slopes  of  the  valley  were  formed,  is  far  to  the  north,  and 
concealed  from  view.  Apparently  at  our  feet,  but  in  reality  a  mile  in 
vertical  descent  below,  lies  the  lake,  a  silent  and  motionless  plain  of  blue. 
Should  the  wind  chance  to  be  strong  in  the  valley,  however,  its  surface 
would  be  rallied,  the  flash  of  breaking  waves  would  reach  the  eye,  and 
long  lines  of  froth  would  streak  its  surface.  At  such  times  abroad  fringe 
of  snowy  foam,  produced  by  the  cluuiiing  of  the  alkaline  waters,  encircles 
the  shores  and  renders  their  outlines  unusually  distinct.  Apparently 
floating  ou  the  surface  of  the  lake,  there  are  two  conspicuous  islands,  the 
forms  of  which  show  that  they  are  of  volcanic  origin.  That  these  craters 
were  built  since  the  encircling  waters  fell  below  their  level,  is  shown 
by  their  unbroken  contours  and  by  the  absence  of  terraces  on  their  outer 
slopes. 

Beyond  the  lake  the  In'own  and  barren  land  seems  low  and  feature- 
less, because  of  the  elevation  of  our  i)oint  of  view.  We  can  see  far  be- 
yond the  limits  of  the  drainage  basin,  in  which  we  are  now  specially 
interested,  land  distinguish  many  of  the  desert  ranges  of  Neviula  rising 
above  the  purple  haze  enshrouding  their  base;-'  and  obscuring  the  lifeless 
lands  between.  The  highest  of  these  distant  summits,  which  ai)pears  like 
a  spectral  mountain  floating  in  the  sky,  is  even  higher  than  the  peak 
on  which  we  stand,  but  its  naked  sides  are  scorched  to  a  cinder-like 
redness  by  the  desert  heat,  and  no  silvery  stream  can  l)e  detected  in 
the  wild  gorges  scoring  its  flanks.  Its  summit  is  seldom  cloud-cap] )ed, 
and  only  in  the  depth  of  winter  is  its  ruggedness  concealed  by  a 
mantle  of  snow. 

To  the  right  of  the  lake  is  a  long  range  of  craters  built  of  fr.agment8 
of  volcanic   rock   tlirown  out  during  many  violent  eruptions,  and   now 


(t  r 

H 


86 


LAKKS   OF    NORTFI    AMEUirA. 


B 


1 1 


formiiiif  '-'onioiil  piles  witli  ^nicefully  Hwcepiiij,'  outlines.  Several  of  these 
now  s  lent  volciUMU's  rival  Vesuvius  in  luMjjflit  and  l)eauty,  hut  from  our 
elevated  stations  we  can  look  down  upon  the  dejiressions  in  tiieir  sununits, 
and  the  ehiire  ranj^e,  althouj^h  two  miles  in  len<ifth,  with  peaks  risin;^' 
thi'ee  thousand  feet  ahove  the  lake  that  hathes  its  feet,  is  hut  a  minoi' 
feature  in  the  extendetl  landscape. 

Northwest  and  southeast  from  the  summit  of  Mt.  Dana  the  crest  lint! 
of  the  Sierras  is  nuirked  hy  mountain  after  moiintaln  as  far  as  the  eye  can 
reacii.  Turninf,'  soiith  \  f  have  in  view  a  line  example,  thoujfh  not  the 
very  finest,  of  the  wild  and  lu^^^'ed  IIi<,di  Sierras.  At  the  western  hase  of 
the  Mount  Dana  there  is  a  deej),  pictures(pu'  valley,  dotted  with  lakes 
and  traced  hy  ;,"'l''ainin^-  streams.  I^ike  nearly  all  of  the  more  pronounced 
(h'pressions  in  the  ili<fh  Sierr.is.  this  valley  owes  its  ori^^in  principally  to 
stream  erosion,  ami  is  a  relic  of  an  ancient  drainagt;  system,  hut  has 
])een  eidarfjfed  and  its  mii'or  features  modilied  hy  ice  ahrasitai.  At  one 
time  it  was  oeeu[)ied  hy  a  ^dacier,  which  formed  a  part  of  a  ^reat  system  of 
ice  fields  that  covered  all  of  the  Hi^di  Sierras  and  sent  many  ice  streams 
hoth  to  the  east  and  west,  throutrh  precipitous  gorges  to  the  valU-ys 
helow. 

The  rocks  forming  the  nearer  slopes  as  one  looks  toward  the  more 
rugged  jtortion  of  tin;  range  are  of  varied  character  and  rich  in  color;  hut 
farther  within  the  heart  of  the  nu>untains  the  monotonous  gray  coloring 
of  granite  is  hut  partially  concealed  hy  the  scanty  forests  in  the  canons 
and  valleys,  or  hy  the  mosses  and  lichens  on  the  highei-  snnxmits.  Near 
at  hand,  hut  across  a  deep  intervening  valley,  rises  Mt.  Conuess,  hare, 
rugged,  a'ld  grand.  Twelve  miles  to 'the  •■•outli,  across  a  fragment  of 
deeply  ;':oded  tahle-land,  named  the  Kuna  crest,  are  the  spire-like  peaks 
of  Mts.  Lyell  and  Hitter.  Thi'oughout  the  year  their  summits  ari  white 
^1  ith  snow,  and  small  glaciers  can  he  distinguished  in  the  folds  of  their 
lUgged  sides.  Keturning  from  this  vision  of  wild  magniiicence,  the  eye 
rests  upon  a  scene  hundjler  in  its  charms  hut  not  less  pleasing.  Between 
the  naked  crags  forming  the  summit  from  which  we  have  gained  our  com- 
manding view,  and  the  highest  limit  of  the  i)ines,  all  twisted  and  deformed 
from  unequal  struggles  with  wind  and  di-ifting  snow,  there  is  a  helt  of 
rugged  i)recipices  and  weather-heaten  rotdvs  that  at  certain  seasons  are 
hright  with  lichens  and  fringed  with  the  purple  and  gold  of  alpine  hlos- 
soms.  These  charming  decorations  on  the  mountain-'s  hrow  flourish  with 
rank  luxuriance  in  every  cranny  and  cleft,  and  not  infrequently  are  in 
such  rich   profusion  that  an  entire  sunnnit-peak  is  tinted  hy  them  sis 


UELATION    OF    LAKKS    TO   CLIMATIC   CONDITIONS. 


87 


of  these 
nun  oiir 
uminits, 
:s  rising 
a  luiiioi' 

rest  line 
eve  ciiii 

I  not  the 

II  liase  ut 
itli  liikes 
iiioiliited 
•il)ally  to 

Init   lias 

At  one 

system  ot" 

J  streams 

le  valleys 

the  more 
olor;  l)ut 
coh)ring 
I'  canons 
Its.     Near 
ess,  l)are, 
[u-nient  of 
ike  iteaks 
larc  white 
[s  of  their 
;,  the  eye 
lietweeu 
our  eom- 
Idt'formed 
|a  belt  of 
Lsons  are 
|)iue  hh)s- 
rish  with 
|ly  are  in 
them  as 


with  a  twilijrlit  gh)W.  Tn  thcwe  eh'vated  regions  May-tlay  is  a  festival  of 
late  summer,  l»nt  it  Itrings  with  it  a  nuiltitude  of  charms  that  are  unknown 
to  dwellers  in  the  woild  helow. 

'Die  mountains  h"ld  out  innnmeral)l(!  charms  to  detain  us,  hut  we 
must  desci'nd  in  our  fireside  journey,  and  learn  more  of  the  strange  lake, 
the  setting  of  which  was  revealed  from  our  station  on  the  mou'ilaiii  top. 
Our  downward  journey  is  through  a  dee[)  goige  witli  nearly  verticuil  \>alls; 
ii;  its  bottom  a  swift,  clear  stream  plunges  from  ledge  t(»  ledge,  and  rusiics 
through   I'ocky  clia..in.s  witli  a  roar  that  never  allows  the  echoes  of  the 

'  veals 


illV 


It 


Th 


stream  of  cold,  delicious  wat« 


^  ause 

the   chiiractci'   of  many  creeks  and  rivulets   that  are   rushing  down   the 
mountain  side  to  the  ever-thirsty  valley  ])elow. 

A  few  springs  add  their  waters  to  the  supply  from  the  mountains, 
but  none  of  them  are  saline,  and  their  united  volume  is  far  less  thnn  the 
volume  of  any  one  of  lialf-a-dozcn  of  the  mountain  torrents  pouring  into 
Mono  lake.  The  present  density  of  the  lake  water  is  the  result  of  tiie 
long  concentration  by  eviii)oration  of  the  supply  from  the  mountains. 

The  area  of  Mono  lake  in  the  stunmer  of  iSIS:},  was  <S7  s(juare  miles, 
but  varies  with  the  seasons  and  also  from  year  to  year.  As  may  be 
learned  from  the  accompanying  map,  its  north  and  south  axis  measures 
11,  and  its  east  and  west  a>:is  14  miles.  Its  surface  is  broken  by  two 
volcanic  islands  and  by  immerous  crags,  some  of  which  are  renniants  of 
islands  now  nearly  eroded  away,  Avliile  others  are  formed  of  calcareous 
(U'ltosits  precipitated  about  submerged  si)rings.  The  soundings  given 
on  the  mai),  show  that  its  maximum  dei)th  is  1.52  feet,  and  the  mean 
depth  about  01  or  (52  feet,  its  elevation  above  the  sea,  when  surveyed 
in  1885,  was  0380  feet. 

In  Pleistocene  ^imes,  Avhen  great  glaciers  descended  from  the  High 
Sierras  and  were  ];)roh)nged  several  miles  into  the  valley,  the  ratio  between 
inflow  and  evaporation  Avas  changed,  and  the  lake  rose,  but  never  sulli- 
ciently  to  discover  au  outlet.  During  the  time  of  its  greatest  expansion, 
it  had  an  area  of  310  S(|uare  miles,  and  formed  an  unbroken  water  surface 
28  miles  long  from  north  to  south,  and  18  miles  broad.  Its  maximum 
depth  was  then  over  800  feet. 

The  facts  of  greatest  interest  in  connection  with  Mono  lake  are  to  1)6 
found  in  its  chemical  history.  As  sl;own  in  tlie  analvsis  of  its  watei-s 
given  on  page  72,  it  is  strongly  imi)rf.gnated  with  sodium  and  with  car- 
bonic and  sulphuric  acids.  The  most  probable  combination  of  these  and 
other  substances  present  in  the  watei's  is  given  below : 


;i  1 


68 


LAKES   OF   NOKTH   AMERICA. 


Hypothetical  CoMrosrnox  ok  tiik  Watkr  of  ^Iono  Lakk. 

BV    T.    M.    (HATAKn.l 


CONHTITIKNTH. 

(iKA.M.S   IN'   A   LiTEIt. 

Pkk  <  kxt  of  Total 

ISOUDH. 

Silica,  SiO.,  .         .         .         .         . 
Aluiiiiuuin  and  ferric  oxide  (Al2Fe2)03 
Calcium  cailn-iiato,  CaCO,,   . 
Majiiicsiiiiii  carliimatc,  MgCOj 
Sodium  l)()rati'.  Xa^H/)j 
I'otassium  clilfjridc,  KCl 
Sodium  chloride,  NaC'l 
Sodium  sulpliatc,  Xa^SO^     . 
S;diiim  carbonate,  XajCC^g  . 
Sodium  bicarbonate,  NallCOj 

[Specific  gravity,  1.045.] 

0.0700 
0.0030 
0.00.")0 
0.192S 
0.2071 
l.H3(i.-) 

lS..-)033 
9.8(190 

18.3506 
4.385() 

0.13 

0.005 
0.09 

0.3()        : 

0.39    ■ 

3.44 
34.(10 
18.45 
34.33 

820 

53.4729 

100.00 

As  may  be  seen  in  the  above  table,  sodium  carbonate  and  ])i('arbonahe 
form  42.53  per  cent  of  tlie  total  salts  held  in  solution.  The  total  qnan- 
tity  of  theee  salts  contained  in  the  lake  is  estimated  a+  92  million  tons, 
the  total  saline  content  being  2  45  million  tons. 

Owing  to  the  cost  of  transportation  and  the  high  price  of  labor,  tliis 
brine  is  not  now  ntilized,  but  it  forms  a  reservoir  that  may  be  drawn  u})on 
in  the  future.  The  waters  of  Owens  lake,  situated  a  hundred  miles  south 
of  Mono  lake,  Avhere  the  commercial  conditions  are  somewhat  more  favor- 
able, is  already  the  basis  of  a  large  soda  industry.  Two  small  lakes  on 
the  Carson  desert,  known  as  the  Ragtown  ponds,  or  Soda  lakes,  also 
furnish  large  quantities  of  sodium  carbonate  and  bicarbonate.  Tliere  are 
also  several  other  lakes  of  the  same  general  character  in  the  western  part 
of  the  Great  Basin  whicli  have  not  yet  been  found  of  economic  impor- 
tance. One  of  the  most  promising  of  these,  from  a  Cv>mmercJal  point  of 
view,  is  Soap  lake,  in  the  State  of  Washington. 

The  great  abundance  of  sodium  cacbonate  and  bicarbonate  in  Owens, 
Mono,  and  other  lakes  on  the  Avest  side  of  the  Great  Basin,  in  contrast 
with  the  amount  of  these  salts  in  the  brine  of  (Jreat  Salt  lake  and  of  other 
similar  water  bodies  on  the  east  side  of  the  Great  liasin,  is  due  mainly  to 
differences  in  tlu;  character  of  the  rocks  of  the  two  regions.  The  moun- 
tains on  the  west  are  largely  formed  of  volcanic  rocks,  and  yield  alkaline 

1  Ainer.  Jour.  Sci.,  3d  Ser.,  vol.  36,  1888,  p.  149. 


[: 


Total 


i. 


L'arbonahe 

till  qu.ui- 

ion  tons, 

iil)(»r,  this 
wii  upon 
les  south 
)re  fiivor- 
Likes  on 
kes,  also 
liere  are 
tern  part 
10  inipor- 
point  of 

Owens, 
contrast 
of  other 
[lainly  to 
lie  nioun- 
alkaline 


?' 

t> 

cc 

a 

r, 

U- 

X 

1 

C 

< 

2. 

o 

S* 

rr. 

u 

n 

3 

^ 

■t; 

n 

" 

o 

^ 

« 

ii 

'W 

:^ 

s 

<• 

« 

1 

.a 

3 

c« 

ii 

a 

Pr, 

c 

3 

X 

RELATION   OF    LAKES    TO   CLLMATIC   CONDITIONS.  89 

salts  to  the  waters  flowing  over  them  or  percolating  through  their  inter- 
stices ;  while  tlie  rocks  of  tlie  eastern  area  are  hugely  .se.Unientary  in 
origin,  and  supply  sodium  chloride  in  excess  of  sodium  ^arhonate. 

Ihe  cliemieal  liistory  of  the  lakes  of  the  Arid  region  is  not  only  an 
interesting  an.l  attractive  study,  but  one  of  great  economic  importance, 
as  they  hold  an  alnmst  unlimited  supply  of  common  salt,  and  of  sodium 
ca.oonate  and  bicarbonate,  sodium  sulphate,  and  other  salts  in  less  abun- 
dance. Ihis  supply  is  still  farther  augmented  bv  the  deposits  of  former 
akes  now  evaporated  to  dryness.  The  salts  precipitated  from  these  ex- 
tinct lakes,  in  some  instances,  whiten  the  surfaces  of  desert  valleys,  but 
more  frequently  they  are  buried  beneath  or  absorbed  in  the  clays  forming 
the  smooth  plains  left  l)y  the  evaporation  of  playa  lakes  • 

The  importance  of  the  lakes  of  the  Arid  region  to  those  interested  in 
salt  and  alkali  industries  is  so  great  that  the  table  on  page  72  has  been 
inserted  to  show  the  comparative  values  of  the  brines  thus  far  analyzed. 
More  detailed  information  in  this  connection  may  be  found  in  the  inibli- 
cations  cited  below.^ 

r   S  rini    J  «M  ■  .  •  ^"'''■'  ^^^^^^g'-aPh  ^o.  11.  _  I.  C".  Hussell,  "  Lake  Mono  " 

l.  S.  (,eol.  Surv.,  8th  Ann.  Hep.,  188(i-87,  pp.  287-200  _T  r   p„sc„ii   "  i. 
Waahino-ton  "  TT   e  n^^i    c  ,.  ,.    .  ''l'^'"''"'  ^.'.'- —  L  L.  Kussell,     Keconnoi.ssance  n 

Washington      U   S.  Geol.  Surv.,  Bulletin  No.  108.  -T.  M.  Ciatan'   "Natural  Soda  "  V   S 
(.01   Surv.,  Bulletin  No.  60. -T.  M.  Chatard,  "  Analyses  of  the  Water  of  slrAme  ica^ 

Wa^Oreat  Salt  .^,  .eho;/:i  ^^^?C^^^^:LC:S'^:1^ 


CHAPTER   V. 


THE  LIFE  HISTORIES  OP  LAKES. 

Lakes,  like  many  other  features  of  the  earth's  surface,  as  stated 
in  our  introductory  clia[)ter,  have  their  periods  of  growth,  adolescence, 
maturity,  decadence,  and  old  age  leading  to  extinction. 

The  lives  of  most  lakes  are  so  long  that  human  records  cover  only  a 
small  portion  of  their  histories,  hence  their  growth  and  decadence  can 
seldom  he  traced  by  observing  a  single  individual.  By  studying  many 
examples,  however,  in  various  stages  of  development  and  decline,  we 
are  enabled  to  obtain  separate  links  in  the  cliain  of  their  existence,  and 
may  determine,  at  least  in  outline,  the  general  course  that  they  run.  li}- 
having  the  theoretical  history  of  a  normal  lake  in  mind,  one  is  enabled  to 
determine  the  period  of  life  attained  by  .any  special  example  that  may 
be   studied. 

The  histories  of  all  lakes  are  far  from  uniform.  There  are  various 
accidents,  as  they  may  be  termed,  which  introduce  new  conditions,  and 
may  renew  their  j'outh  or  hasten  their  decline.  In  general,  lakes  may  be 
grouped  in  two  great  classes,  in  each  of  which  the  rule  they  play  is  in 
th(!  main  the  same.  The  differences  in  the  lives  of  these  two  classes 
depend  mainly  on  climatic  conditions,  and  have  been  noticed  in  descril)- 
ing  fresh  lakes  and  terrestrial  saline  lakes.  The  destiny  of  a  lake  born 
beneath  humid  skies  runs  in  a  somewhat  definitely  prescribed  channel  and 
(lej)arts  in  a  marked  way  from  the  more  varied  life  of  a  lake  originating  in 
an  arid  region.  Tlie  general  outline  of  the  history  of  each  of  the  two 
classes  referred  to  is  briefly  as  follows :  . 


Lakes  of  liiiniid  Ite^'ioiis.  —  The  normal  lakes  of  humid  regions 
are  comparatively  short-lived.  The  streams  tiibutary  to  them  bring  iu 
sediments  which  tend  to  fill  their  basins,  to  these  are  added  the  debvis 
of  water-loving  plants  and  the  hai'd  paits  of  animals,  and  at  the  same 
time  the  streams  flowing  from  them  tend  to  cut  down  their  outlets  and 
drain  them  at  lower  and  lower  levels.  Two  processes  thus  conspire  to 
diminish  their  volumes  and  shorten  their  existence.  The  deposition  of 
sediment  on  their  bottoms  usually  leads  to  their  extinction  more  quickly 


THE   LIFE    HISTORIIIS   OF    LAKES. 


91 


IS  stated 
lescence, 

31-  only  a 
ence  can 
iig  many 
I'line,  we 
3nce,  and 
run.  By 
nabled  to 
that  may 

re  various 
ions,  and 
s  may  be 
ay  is  in 
o  classes 
desei'il)- 
xke  born 
unci  and 
lating  in 
the  two 


regions 
I  bring  i'l 
lie  debvis 
[he  same 
[lets  and 
Ispire  to 
isition  of 

(quickly 


than  the  lowering  of  tlieir  outlets,  for  the  reason  that  while  incoming 
streams  are  frecjuently  turbid  and  heavy  with  sediment,  the  outgoing 
waters  are  clear  and  tlierefore  have  Imt  little  power  to  erode.  The  clear 
outflowing  waters  deepen  their  cliannels  l)y  the  slow  process  of  chemical 
solution,  but  when  the  rocks  over  which  tliey  pass  are  soft  and  inco- 
herent, they  may  soon  become  recharged  witli  sediment  and  make  rajjid 
progress  in  deepening  their  channels  and  in  draining  the  basin  al)ove.  Tlie 
lives  of  various  lakes  may  (lifter  in  length  and  liave  minor  variations 
according  to  local  conditions,  but  tlie  main  features  in  their  histories  will 
conform  to  the  same  general  outline. 

The  filling  of  lake  basins  by  sediment  fie(][uently  progresses  more 
rapidly  than  at  fii-st  might  be  supposed.  In  some  instances  its  rate 
may  Ije  observed  from  year  to  year,  and  attracts  the  attention  of  even  the 
casual  observer.  In  countries  that  have  l)een  long  inhabited,  there  is 
sometimes  histtnical  evidence  of  the  rate  at  which  the  boundaries  of  lakes 
have  contracted.  At  the  head  of  Lake  Geneva,  Switzerland,  for  example, 
the  Rhone  is  bringing  in  large  (quantities  of  silt  derived  from  the  gl<i- 
ciers  on  its  head  waters,  and  a  low  grade  delta  is  being  extended  into  the 
lake.  As  stated  by  Lyell,^  the  town  of  Port  Vallais  (Portus  Valeste  of 
tlie  Romans)  once  situated  at  the  water's  edge,  is  now  more  than  a  mile- 
and-a-half  inland,  tliis  exteiisi'in  of  the  shore  having  been  made  in 
about  eight  centuries. 

The  decrease  in  the  ca[)acity  of  lake  basins,  in  ordinary  cases,  goes  on 
so  much  more  rapidly  from  tilling  than  from  the  lowering  of  their  outlets, 
that  it  is  the  destiny  of  most  lakes  situated  in  humid  regioi.s  to  l)ecome 
exterminated  mainly  l)y  sedimentation.  I>y  this  [)rocess  their  basins  are 
transformed  into  alluvial  plains,  through  whicli  wander  the  streams  that 
were  tributary  to  the  antecedent  lakes.  'I'liese  streams  l)eing  no  longer 
robbed  of  the  material  they  carrv  in  susj)ension.  are  enabled  to  attack 
their  channels  l)elo\v  the  forme/  lakes  with  energy,  and  to  deepen  and 
broaden  them.  The  grade  of  the  streams  through  the  alluvial  ])lain, 
marking. the  former  site  of  a  lake,  is  increased,  aiiil  the  removal  of  the 
soft  lakebeds  progresses  as  the  channel  belo\\'  is  deepened.  Streams  flow 
through  alluvial  })lains  with  slackened  speed,  and  form  winding  channels, 
and  swing  from  side  to  side  of  their  valleys,  thus  reducing  the  general 
level.  The  load  j)reviously  deposited  in  the  basin  is  again  taken  up  and 
the  deferred  task  of  transporting  it  to  the  sea  is  resumed.     Former  lake- 

1  Principles  of  Geology,  11th  edition,  1873,  vol,  1,  p.  413. 


m 


LAKES   OF   NORTH   AMEKICA. 


I    I 


basins  thus  become  terraced  valleys,  with  streams  winding  through  them 
in  broad  curves,  and  in  civilized  regions  afford  rich  farming  lands  and 
charming  sites  for  towns  and  cities. 

At  a  later  period,  if  some  outsiile  influence  does  not  change  the  course 
of  history,  the  alluvial  deposits  are  dissected  to  the  bottom,  the  terraces 
of  soft  material  are  removed,  and  all  records  of  the  once  beautiful  lake 
may  be  lost.  This  transformation  maj*  require  tens  of  thousands  of  years 
for  its  completion,  yet  the  end  is  inevitable.  The  various  stages  in  this 
general  history  might  be  illustrated  by  an  abundance  of  examples.  Thou- 
sands of  lakes  in  the  formerly  glaciated  region  of  northeastern  America 
still  retain  the  freshness  of  youth,  and  their  nearly  level  bottoms  may  be 
considered  as  unborn  lacustral  plains.  The  terraced  borders  of  Lake  Cham- 
plain,  and  of  the  Laurentian  lakes,  mark  the  former  extent  of  water 
bodies  that  have  passed  the  youthful  stage.  Many  terraced  valleys  in  the 
Cordilleras  record  the  former  presence  of  lakes  in  basins  that  are  now 
completely  drained.  In  other  localities,  as  in  the  "  Parks  "  of  Colorado, 
no  terraces  may  be  distinguished,  but  vestiges  of  lacustral  sediment  still 
floor  their  bottoms.  Many  valleys  in  the  same  region  drain  through 
narrow  stream-cut  gorges,  but  all  other  evidence  of  their  having  been 
formerly  water-filled  has  vanished.  The  time  required  for  these  muta- 
tions is  vast  when  reckoned  in  years,  but  to  the  geologist  they  are 
transient  phases  in  the  topographic  development  of  the  land. 

The  even  course  of  history,  outlined  above,  may  be  varied  somewhat, 
as  when  the  outflowing  stream  is  rapid  and  especially  when  falls  occur  in 
its  course.  Waterfalls  are  formed  especially  where  streams  flow  over 
nearly  horizontal  strata  where  a  hard  surface  layer  rests  upon  shales  or 
other  easily  eroded  beds,  as  is  typically  illustrated  at  the  Falls  of  Niagara. 
The  ujulermining  of  the  hard  capping  layer  is  effected  by  the  removal  of 
the  soft  beds  beneath,  and  blocks  from  the  brink  of  the  precipice  fall  to 
the  pool  below  and  assist  the  swirling  water  to  deepen  a  basin.  A  fall 
thus  cuts  back  the  ledge  over  which  it  plunges  with  comparative  rai)id- 
ity,  —  in  the  case  of  Niagara  the  rate  of  recession  is  from  4  to  6  feet  per 
year,  —  and  may  lead  to  the  drainage  of  a  lake  before  its  basin  has  been 
deeply  filled  with  sediment.  The  succession  of  the  principal  events  in  the 
hist  jry  of  a  valley  may  thus  be  hastened,  but  the  ultimate  results  will  be 
essentially  the  same. 

Many  small  lakes,  especially  in  forested  countries,  where  the  surface 
waters  filter  through  layei-s  of  vegetable  d^'bris  before  gathering  into  rills 
and  brooks,  are  filled  mainly  by  organic  agencies.     Water  plants,  and 


THE   LIFE   HISTOIIIES   OF   LAKES. 
I 


98 


iprh  them 
luds  anil 

he  course 
B  terraces 
tiful  hike 
s  of  years 
;es  in  this 
i.  Thou- 
1  America 
lis  may  he 
ike  Cham- 

of  water 
eys  in  the 
,t  are  now 

Colorado, 
iment  still 
1  through 
ving  heen 
lese  muta- 
,  they  are 

somewhat, 

[s  occur  in 

flow  over 

shales  or 
if  Niagara, 
'emoval  of 
lice  fall  to 
In.  A  fall 
ive  rapid- 
[6  feet  per 
has  been 

iUts  in  the 
[its  will  he 

the  surface 

into  rills 

lants,  and 


especially  Sphnf/num  or  peat  moss,  grow  about  their  shores,  and  extend- 
ing outward,  form  a  thick  mat  of  intertwined  roots  and  stems  that  float  on 
the  surface.  The  finer  Avaste  from  this  sheet  of  floating  verdure  falls  to 
tlie  bottom  and  forms  a  peaty  stratum.  To  this  layer  contributions  are 
made  by  other  aipiatic  vegetation,  as  the  lilies,  reeds,  rushes,  and  many 
beautiful  siilKXciuatic  plants.  It  also  receives  the  trunks  of  trees  falling 
from  the  shore.  The  small  lakes  of  the  prairie  region  especially,  are  fre- 
quently transformed  in  this  manner  into  1'  tutifnl  fields  of  wild  rice.  In 
the  central  part  of  moss-encircled  lakes,  practically  no  mechanical  sedi- 
ments are  t1e[)osited,  but  mollusks,  crustaceans,  and  fishes  may  tliere  find 
a  well  sheltered  home  and  thrive  in  such  abundance  that  the  bottom  soon 
becomes  covered  with  their  remains.  Microscopic  forms  also  inhabit  the 
water  and  their  siliceous  cases  frecpiently  accumulate  so  as  to  form  thick 
la}  ers,  known  as  diatomaceous  earth.  A  continiuition  of  this  process  under 
favorable  conditions  leads  to  the  rapid  extinction  of  small  lakes.  Tlie  o[)en 
waters  are  converted  i.ito  hoga  and  swamps,  on  which  forest  trees  encroach 
and  still  farther  assist  in  the  transformation.  When  these  de^josits  of 
organic  matter  are  drained,  they  frequertly  furnish  rich  garden  lands. 
The  lakes  exterminated  by  this  organic  process  in  the  drift-covered  por- 
tion of  North  America,  can  only  be  estimated  in  tens  of  thousands,  and 
probably  equal  in  number  the  lakes  still  remaining. 

Lakes  of  Arid  Regions.  —  On  every  continent  there  are  broad  areas 
where  the  skies  are  without  a  storm  cloud  for  many  months  each  year  and 
the  air  is  dry  and  hot  in  all  but  the  winter  season.  The  lakes  in  tliese 
desert  regions  have  a  different  general  history  from  their  sisters  whose 
banks  are  fringed  with  green  vegetation  and  overshadowed  by  forests. 
Where  the  rainfall  is  small  and  e"»'aporation  active,  the  lives  of  lakes 
depend  on  delicate  adjustments  of  climatic  conditions.  As  the  barometer 
rises  and  falls  in  harmony  with  changes  in  atmos[)heric  pressure,  so  en- 
closed lakes  fluctuate  in  sympathy  witli  changes  in  humidity  or  in  tem- 
perature. The  ephemeral  lives  of  playa  lakes  have  already  been  described, 
but  the  larger  lakes  of  arid  regions,  although  subject  to  many  fluctuations, 
may  have  a  longer  span  o^  existence  than  lakes  of  corresponding  size  and 
similar  topographic  environment  in  humid  regions.  As  enclosed  lakes  do 
not  overflow,  there  is  no  loss  of  area  owing  to  the  lowering  of  outlet. 
Tributary  streams  bring  in  material  both  in  solution  and  in  suspension,  all 
of  which  is  left  as  evaporation  progresses,  and  tends  to  fill  their  basins, 
but  the  volume  of  their  waters  is  not  directly  diminished  by  this  process. 


!»4 


LAKES    OF    NOUTH    AMKUICA. 


i';  I 

f' 
f  I 


As  their  basins  are  filled,  however,  the  watere  expand  and  offer  a  greater 
snrface  to  the  atmosphere,  thus  promoting  eva|)orati()n.  A  continuanct' 
of  this  process  results  in  so  enlarging  the  water  surface  that  in  time  evap- 
oration e(pials  the  snp[)ly  and  the  water  hody  i)assi's  to  the  condition  of  a 
playa  lake.  Sedimentation  may  raise  the  water  surface  so  that  an  outlet 
is  found  before  the  playa  stage  is  reached,  thus  transferring  an  enclosed 
and  saline  lake  to  the  class  normal  to  humid  regions,  already  considered. 

The  existence' of  lakes  in  (;ountries  where  there  is  a  close  adjustment 
between  precipitation  an<l  eva[)oi'ation,  is  also  controlled  largely  by  topo- 
graphic conditions.  It  may  be  said  that  this  is  the  primary  condition  that 
determines  whether  lakes  shall  exist  in  arid  regions  or  not.  This  is  true, 
if  we  consider  the  origin  of  the  lake  basins,  and  also  important  if  the  ex- 
istence of  lakes  in  rea<ly-fornied  basins  is  discussed,  since  the  topography 
has  a  direct  and  frequiiitly  controlling  influence  on  rainfall  and  on  evapo- 
ration. The  influence  of  topograi)hy  is  also  marked  in  determining  the 
ratio  of  the  area  of  a  basin  to  the  area  of  the  lake  in  its  lowest  depres- 
sion. The  hydrographic  basins  of  enclosed  lakes  as  a  rule  are  large  in 
reference  to  their  water  surfaces,  when  compared  with  the  ratio  of  catchment 
areas  to  lake  areas  in  humid  regions.  Any  change  tending  to  diminish 
the  aref  '  .ibutary  to  an  enclosed  lake,  as  the  sapping  of  the  head  waters  of 
its  tributary  streams,  Avoidd  have  a  marked  influence  on  its  history. 

Episodes  of  another  character  also  occur  in  the  lives  of  enclosed  lakes. 
The  salts  slowly  accumulated  in  them  may  not  only  be  flooded  out  by 
overflow  consequent  on  changes  in  to[)ography,  or  on  an  increase  in  rain- 
fall, or  on  a  decrease  in  evaporation,  but  aiay  be  eliminated  by  reason  of  a 
reverse  change  in  the  ratio  of  inflow  to  evaporation.  A  decrease  in  humid- 
icy  or  an  increase  in  evaporation,  or  what  is  probably  more  frequent,  a 
combination  of  these  two  processes,  may  reduce  a  lake  to  the  playa  stage. 
When  this  occurs,  its  salts  will  be  precii)itated  and  may  become  buried  or 
al)sorbed  by  sediment,  so  that  when  a  new  lease  of  life  is  granted  and  the 
waters  expand  and  form  a  perennial  lake,  tliey  are  fresh,  or  essentially 
so,  and  start  anew  in  the  process  of  concentration.  Still  other  changes 
that  beset  the  lives  of  enclosed  lakes  might  be  enumerated,  to  show  tliat 
they  are  subject  to  greater  vicissitudes  than  their  sister  lakes  in  more 
favored  lands. 

When  the  lakes  of  arid  regions  become  extinct,  either  by  reason  of 
evaporation  or  sedimentation,  the  evidence  of  their  former  existenci' 
remains  inscribed  on  the  inner  slopes  of  their  basins  or  concealed  in  the 
strata  deposited  over  their  bottoms.     These  records  as  a  rule  are  much 


•■;ii.| 


THK    LIFE   HISTOllIES    OF   LAKES. 


96 


a  greater 
ntiniiance 
:iinc  evap- 
litioii  of  a 

an  outlet 
1  enclosed 
onsidered. 
djnstnient 
y  by  topo- 
Llition  that 
lis  is  true, 

if  the  ex- 
opogra])hy 

on  evapo- 
iiining  the 
ist  depres- 
e  large  in 
catchment 

0  diminisli 

1  waters  of 

ory. 

)sed  lakes. 
id  out  hy 
■ie  in  rain- 

•eason  of  a 
in  humid- 
requent,  a 
aya  stage, 
buried  or 
id  and  the 
ssentially 
r  changes 
show  that 
Is  in  more 

reason  of 

existence 

led  in  the 

[are  much 


more  lasting  than  those  left  by  lakes  in  humid  lands,  for  the  reason  that 
the  climatic  conditions  are  less  destructive.  The  terraces  and  embank- 
ments of  gravel  left  by  lakes  in  desert  valleys  are  especially  permanent 
topograjihic  features,  as  the  scanty  rain  that  falls  on  them  is  absorbed  and 
allowed  to  percolate  slowly  through  them,  instead  of  flowing  down  their 
surfaces  so  as  to  erode.  Tiie  sediments  deiM>sitcd  in  enclosed  basins  are 
also  protected,  from  destruction,  as  they  cannot  be  removed  by  streams 
until  some  change  inaugurates  free  drainage  to  the  sea  or  to  some  lower 
basin.  A  continuation  of  aridity  in  a  desiccated  lake  basin,  results 
normally  in  the  burial  of  the  lacustral  sediments  beneath  subaerial 
de[»osits,  thus  again  insuring  their  preservation.  To  follow  this  subject 
farther  would  lead  to  a  comparative  study  f>f  the  processes  of  erosion  in 
arid  and  in  humid  regions,  which  is  beyond  the  scope  of  the  present  essay. 

It  will  be  seen  from  what  has  been  presented  above  with  reference  to 
the  normal  course  of  the  lives  of  lakes,  that  in  s])ite  of  the  many  varia- 
tions they  present,  the  seeds  of  death  are  planted  at  their  birth,  and  they 
are  destined,  sooner  or  later,  to  pass  away  and  give  place  to  other  condi- 
tions. 

Interruptions  of  the  even  tenor  of  the  lives  of  lakes,  in  lioth  arid  and 
humid  regions,  such  as  the  effects  of  u[)heaval  and  depiessicm  of  the  earth's 
crust,  earthquakes  and  volcanic  erui)tions,  might  be  considered,  bat 
these  abnormal  incidents,  like  the  acicidents  in  human  lives,  cannot  be 
foretold,  and  apply  to  individuals  rather  than  to  classes. 


CHAPTER   VI. 


3 


STUDIES    OF    SPECIAL    LACUSTRAL    HISTORY. 

It  will  iippear  to  the  reader  of  the  i)reee(liiig  elmpter'  that  not  only 
are  lakes  ephi  iiieral  features  of  the  earth's  surface,  but  even  the  changes 
they  make  in  the  to[)Ocrraphy  of  their  shores,  altliougli  perliaps  engraved 
in  solid  rock,  are  of  shox '.  duration  in  comi)arison  with  the  length  of  the 
eras  into  which  the  earth's  history  lias  been  subdivided.  Tiie  lakes  of 
Pleistocene  times,  liowever,  left  records  which  in  many  instances  are  still 
legible,  and  form  a  connection  between  historical  and  the  most  recent 
geological  times. 

As  examples  of  extinct  lakes  w-hose  histories  are  still  clearly  legible, 
a  brief  account  will  be  given  of  former  water  bodies  of  the  Laurentian 
l)asin,  and  in  the  region  now  draining  to  Lake  Winnepeg,  Avhere  the 
climate  is  humid,  and  of  two  formerly  extensive  lakes  of  the  Arid  region. 

PLEISTOCENE    LAKF.S    OF    THE    LAUHENTIAN    BASIN. 

Long  curving  ridges  of  gia >'el  having  the  appearance  of  great  railroad 
embankments,  following  the  general  trend  of  the  shores  of  lakes  Ontario 
and  Erie,  but  usually  at  a  distance  of  several  miles  from  their  present 
borders,  wcn-e  noticed  at  an  early  day  in  the  settlement  of  New  York, 
Ohio,  and  Ontario,  and  correctly  interpreted  as  l)eing  the  records  of  previous 
high-water  stages  of  the  lakes  they  encircle.  These  ridges  became  high- 
ways of  travel  as  civilization  advanced,  and  gave  origin  to  the  term  "ridg(! 
road"  still  to  be  seen  on  local  maps  of  the  region  referred  to.  These 
ricif^es  and  other  associated  records  have  claimed  the  attention  of  geolo- 
gists and  others  and  have  been  made  the  subject  of  special  incjuiry.  The 
territory  traversed  by  them  is  so  extensive,  however,  that  their  study  is 
still  far  from  complete. 

The  ancient  beaches  about  lakes  Ontario  and  Erie  have  been  followed 
and  studied,  esi)ecially  by  G.  K.  Gilbert,  in  New  York  and  Ohio,  and  by 
J.  W.  Spencer,  in  Canada.  The  records  of  former  water  levels  north  of 
Lake  Superior  from  Duluth  to  Sault  Sainte  Marie,  have  been  traced  and 
mapped  by  A.  C.  Lawson.  To  the  south  of  Lake  Superior  the  ancient 
shores  have  been  systematically  followed  by  F.  B.  Taylor.     Many  other 


HTUDIKS    (U-     Sl'KClAI.    LACCSTltA  I-    IIISTOKY 


97 


.  not  only 
e  changes 
1  engraved 
(jtli  of  tlu' 
e  lakes  of 
es  are  still 
lost  recent 

rly  legible, 

Liinrentiau 

Avliere  the 

aid  region. 


at  railroad 
es  Ontario 

|eir  present 
■few  York, 

|of  [)revions 
'iune  liigli- 

lerni  "ridge 
:o.  These 
n  of  geolo- 
lury.  The 
lir  study  is 

In  followed 
lio,  and  by 
lis  north  of 
Itraeed  and 
pe  ancient 
llany  other 


observers  have  also  contributed  to  tliis  study,  but  not  in  such  a  methodical 
manner  oh  those  whose  names  have  just  been  mentioned  Some  of  the 
|)roblems  that  have  ])resented  tiiemselves  during  this  investigation  have 
not  yet  been  satisfiictorily  explained,  l)Ut  at  least  an  outline  of  the  I'leis- 
tocene  history  of  the  Laurcntian  basin  may  be  presented  with  the  under- 
standing tliat  it  is  to  be  niodilied  as  additional  facts  are  obtained. 

The  most  dramatic  episode  in  the  geological  history  of  North  America 
was  the  formation  during  I'leistocene  time,  of  glaciers  many  hundreds  of 
feet  in  thickness  over  the  northern  part  of  the  continent.  The  ice  advanced 
from  the  north  and  not  only  covered  the  Laurcntian  biisiii,  l)ut  spread 
southward  beyond  the  southern  border  of  its  watershed.  The  ice  i(»vered 
this  region  with  various  advan(  js  and  retr.ats  tor  thousiuids  of  years,  and 
when  it  linally  withdrew,  the  inunediate  ancest(>rs  of  the  present  (Ireat 
Lakes  were  born.  There  are  severel  observations  tending  to  the  conclu- 
sion that  during  an  interglacial  time  when  the  ice  receded  far  north  of  its 
maxinmm  limit,  lakes  were  formed  in  the  same  basin,  but  in  this  connec- 
tion there  is  little  evidence  to  claim  pofjular  attention. 

Previous  to  the  Glacial  e^joch  or  the  (treat  Ice  age,  as  it  is  frequently 
termed,  the  region  under  review  was  an  old  land  surface  with  riveis  flow- 
ing across  it  to  the  sea.  Its  draini>ge  system  was  well  dcvclo})ed  and  the 
streams  meandered  through  broad  valleys,  bounded  in  part  by  steep  escarp- 
ments. In  general  relief,  it  nuist  have  resend)leil  the  upjier  portion  of  the 
Mississippi  valley  as  it  exists  to-day,  where  the  topogi'aph}-  has  not  l)cen 
modified  by  glacial  action. 

The  conclusion  that  the  Laurentian  region  was  exposed  to  erosion  for 
i  long  period  previous  to  the  Glacial  epoch,  is  based  on  the  character  of  tht- 
ivlief  of  the  hard  rock  surface  now  covered  in  part  by  glacial  deposits  and 
on  the  fact  that  no  sediments  of  younger  date  than  the  C'arlioniferous 
period,  with  the  possible  exceptions  of  terranes  of  Cretaceous  age  in  por- 
tions of  iNIinnesota,  occur  within  its  borders. 

It  may  be  suggested  as  a  tentative  hypothesis,  that  previous  to  the 
rilacial  epoch  the  greate  •  part  of  the  Liiurentian  basin  discharged  il> 
waters  southward  to  the  Mississippi,  and  that  during  the  iirst  iidvance  of  the 
ice  from  the  north,  the  drainage  was  not  obstructed  so  as  to  form  importiini 
lakes.  This  suggestion  rests  in  part  on  the  fact  that  no  lake  deposits 
have  yet  been  found  beneath  the  lowest  sheet  of  glacial  ddl)ris  lining  the 
basin,  —  this  negative  evidence  is  of  little  weight,  however,  as  such 
de})osits,  if  they  exist,  would  be  mostly  beneath  the  present  lakes  and 
therefore  exceedingly  difficult  to  discover, — and  on  the  character  of  an 


98 


LAKES   OF    NOUTII    AMKIIK^A. 


ancient  rivor  viilU'V  IciKlinj,'  sontli  from  (he  sontlicrn  on<l  of  Lake  Micli- 
i^iin,  wliicli  is  ri'itorti-d  to  he  scored  witii  ^liicial  ^toovcs,  and  <il)strnct('d 
by  glacial  deposits.'  As  will  be  iioticccl  below,  tliis  same  channel  wasalsn 
an  ontlet  for  the  waters  of  the  Lake  Michi^mn  basin  in  post-j^lacial  times. 

When  the  jiflaeiei-s  of  the  (Jlaeial  e[)oeh  were  at  their  maxinuim,  the 
<lraina},'e  from  the  iee  fonnd  a  fruo  e-seajte  southward,  as  is  abundantly 
testilied  by  inunense  '  ;osits  of  gravel  that  were  dropped  by  the  over- 
loaded j^lacial  streams,  as  well  as  by  numerous  water-worn  clianiuds  which 
ai'c  too  lar<fe  for  the  streams  now  oceupyinj^  them  and  are  without  water- 
wheds  eonnuensurate  with  their  size. 

As  the  ice  sheet  retreated,  there  came  a  time  when  its  southern  margin 
was  north  of  the  drainage  divide,  passing  in  an  irregular  east  and  west 
direction  through  Central  New  York  and  Central  Ohio,  and  now  [)artiug 
the  wateis  flowing  south  from  those  that  find  their  way  northward  to  the 
Laurentian  lakes.  When  this  occurred,  lit'  'S  were  formed  between  the 
margin  of  the  ice  and  the   high   land  to  t  )Uth.     These  earlier  lakes 

stood  at  various  levels  and  discharged  soui....<a(l  across  the  lowest  depres- 
sions in  their  shores.  Stream  channels  were  excavated  by  the  outflowing 
waters  and  became  deeply  filled  with  gravel  and  sand,  but  in  many  instances 
are  still  clearly  traceable.  One  of  these  ancient  channels  starts  near  Fort 
Wayne.  Indiana,  leads  southwest  and  afforded  an  escape  for  the  waters  that 
accumulated  in  the  western  'portiou  of  the  Krie  basin.  A  similar  outlet 
at  the  south  end  of  the  Lake  Michigan  basin  has  already  been  referred  to. 
Other  points  of  discharge  have  been  reported  at  other  localities  on  the 
southern  margin  of  the  Laurentian  basin. 

As  the  ice  occu})ying  the  Erie-Ontario  basin  withdrew  northward, 
the  Lakes  about  its  margin  expanded  and  became  united  one  with  another. 
Wlien  the  ice  barrier  between  the  two  basins  was  broken  the  higher  lake 
discharged  into  the  lower  one,  and  its  former  outlet  leading  south  was 
abandoned. 

When  a  single  water  body  occupied  the  Erie-Ontario  basin,  the  site  of 
Niagara  river  was  deeply  submerged.  When  the  water  fell  to  the  level 
of  the  Mohawk  outlet,  the  two  basins  became  divided  and  Niagara  river  was 
born.  The  river  from  the  upper  basin  discharged  across  the  lowest  sag 
in  its  rim  and  cut  back  a  deep  gorge,  until  an  old  channel  excavated  in  pre- 
glacial  or  possibly  inter-glacial  times,  was  discovered  and  the  work  of 
extending  it  renewed.     When  the  falls  shall  have  receded  so  as  to  drain 

1  F.arther  evidence  seems  to  be  needed,  liowever,  before  the  presence  of  a  pre-glacial 
channel  leading  south  from  Lake  Miclngiin,  can  be  considered  as  definitely  determined. 


2<i  ^    I 


Lake  Miili- 

(ll).stlll('lf«l 

lu'l  was  also 
acial  tinu's. 
xiiiuiii),  IIm' 
abundantly 
\y  the  ovur- 
niols  whit'li 
liout  watt'i- 

lern  margin 
>t  and  west 
low  [)aitin<^ 
ward  to  the 
etween  the 
arlier  lakes 
vest  de})res- 
outrtowliifj 
ay  instances 
;s  near  Fort 
waters  that 
nilar  outlet 
referred  to. 
ties  on  the 

northward, 

th  another. 

higher  hike 

south  was 

,  the  site  of 
o  the  level 
I'a  river  was 

lowest  sag 
iited  in  pre- 
le  work  of 

as  to  drain 

t  a  pre-glacial 
3nnined. 


y 


i 


[ft 


1 

V 

1( 

o 
n 
e( 

(li 
o> 
>sli 
fo 
ca 
be 

th( 


STUDIES   OF    SPECIAL    LACUSTKAL    HISTORY. 


m 


Lake  Erie  at  a  lower  level  tliiui  at  present,  the  shore  lines  \o\v  forming 
about  its  margin  will  l)e  abandoned  and  another  line  added  to  the  records 
aljout  its  l)ord(jrs. 

For  a  long  period  in  tlie  history  of  the  Ontario  basin,  tlie  outflowing 
water  escaped  through  tlic  Mohawk  valley.  New  York,  as  lias  been  shown 
by  (xilbert,  and  the  discharge  of  a  large  part  of  the  Laurentian  l)iisin 
reached  tlie  seii  by  that  channel.  The  series  of  well  dehned  water-marks 
about  the  O.itario  basin  formed  at  this  time,  has  been  named  the  "  Iroquois 
beach,"  by  Spencer,  and  the  ancient  lake  outlined  by  it  is  known  as  "  Lake 
Irfxpiois."'  When  the  ice  front  retreated  still  farther  northward,  the 
present  course  of  the  St.  Lawrence  was  uncovered,  the  Mohawk  channel 
was  abandoned,  the  water  surface  fell,  and  existing  conditions  were 
establislied. 

During  various  stages  in  the  enlargement  and  subseqiu'nt  contr:iction 
of  the  lakes  about  the  southern  margin  of  the  Laurent'dc  glacier,  beaches 
were  formed  which  in  some  instances,  as  has  been  shown  l»y  Frank  Lev- 
erett,  in  Ohio,  are  continuations  of  the  moraines  deposited  at  the  margin 
of  the  ice  where  lakes  did  not  exist  in  front  of  it.  In  otiicr  instances 
moraines  ojcur  that  are  partially  or  wholly  buried  beneath  lake  sediments 
and  mark  the  boundaries  of  the  ice  front  where  it  was  margined  by  water 
bodies. 

At  many  localities  where  tlie  former  wAter  markings  are  well  pre- 
served, they  were  made  on  low  shores,  and  took  the  form  of  ridges  re- 
sembling railroad  embankments.  The  highest  of  these  ridges  marks  the 
maximum  limit  of  the  water  bod}'  about  which  it  was  formed.  As  the 
water  fell  the  higher  beaches  Avere  abandoned  and  others  constructed  at 
levels  determined  by  lower  outlets.  When  the  bordere  of  the  Ldvcs  were 
of  ice.  shore,  records  are  wanting,  but  as  stated  above,  buried  nioiMines 
may  mark  the  position  of  the  dividing  line  between  the  water  and  the 
C(mfining  ice. 

While  the  ancient  beaches  were  in  process  of  construction  (he  alain- 
dant  sediments  carried  into  the  lakes,  were  s][)read  out  as  slu  ets  of  (.-lay 
over  the  deeper  portions  of  vhe  basin,  and  at  the  same  time  the  areas  near 
shore  received  deposits  of  sand.  Icebergs  broke  away  fnmi  tlie  glaciei-s 
forming  ihe  northern  shores  of  the  lakes,  and  floated  over  their  surfaces, 
carrying  stones  which  were  dropped  as  tlie  ice  melted,  and  became  im- 
bedded in  the  clay  on  the  bottom.  These  dei)osits  surioiiiul  the  ju'esent 
Laurentian  lakes  and  luiderlie  them.  About  the  lioiders  of  Lake  Erie 
they  appear  as  a  stiff  blue  clay, — known  to  geologists  as  the  "  Erie  clay," 


I',- 


100 


LAKES    OF    NOllTH    AMlililCA. 


m 


charged  in  some  instances  with  large  houlders  of  crystalline  rock,  —  and  as 
sheets  of  yellow  sand,  known  as  "delta  sands,"  which  rest  on  the  clay,  and 
are  especially  ahundant  where  the  mouths  of  ancient  streams  were  located. 
Ahont  the  shores  of  Lake  Sni)erior  and  frequently  extending  many  miles 
inland,  there  are  ancient  clay  deposits  of  a  pink  color,  that  were  accumu- 
lated when  the  l«isin  contained  a  much  larger  sheet  of  water  than  at 
present. 

The  heaches  ahout  the  borders  of  the  Laurentian  lakes  were  originally 
horizontal,  but  as  has  been  shown  especially  by  (rilbert  and  S])encer,  they 
are  in  many  cases  no  longer  in  their  original  jjosition.  Changes  in  the 
elevation  of  the  land  liave  occurred  and  the  beaches  liave  been  carried  u[) 
or  down  with  it. 

The  amount  of  change  in  level  shown  by  the  warping  of  the  beaches 
abovit  Lake  Ontario  is  considerable,  and  illustrates  the  character  of  the 
slow  u[)heavings  and  subsidences  known  to  be  in  progress  over  wide  areas 
of  the  earth's  surface.  It  is  stated  by  Gilbert^  that  "the  old  gravel  spit 
near  Toronto,  belonging  to  what  is  known  as  the  Davenport  ridge,  is  forty 
feet  higher  than  the  contemporaneous  gravel  spit  on  wliich  Lewiston  is 
built ;  at  Belleville,  Ontario,  the  old  shore  is  200  feet  higher  than  at 
Rochester  ;  at  Watertown,  N.  Y.,  300  feet  higher  than  at  Syracuse  ;  and 
the  lowest  point  in  Hamilton,  Ontario,  at  the  head  of  the  lake,  is  3"25  feet 
lower  than  the  highest  point  near  Watertown.  Frf)m  these  and  othei' 
measurements  shown  on  I'late  18,  we  learn  that  the  Ontario  basin  with 
its  new  attitude  inclines  more  to  the  south  and  west  than  with  tlie  old 
attitudes."'  This  rj(>neral  tiltinj''  has  throv»n  the  waters  of  Lake  Ontario 
westward  and  flooded  small  tributary  valleys  so  as  to  drown  them  and 
make  miniature  flords. 

Movements  in  the  earth's  crust  Avere  also  in  progress  during  the  long 
period  in  which  the  ancient  lakes  of  the  Laurentian  basin  were  making 
their  various  records,  as  is  shown  by  the  fact  that  the  abandoned  beaches 
do  not  all  lie  in  })lanes  parallel  Avith  es'ch  other. 

The  higliest  of  tlie  ancient  beach  lines  about  the  north  shore  of  Lid<i 
Superior,  has  an  elevation  of  about  000   feet  above  the  present  lake,  as 
has  been  determined  by  A.  C.  Lawson.^     The  beaches  at  lower  levels  arc 

J  "  The  history  of  Xiajjara  river."  in  Sixth  Annual  IJcport  of  tlie  Coniiuissioners  of  tjit 
Rtatc  l.'eservation  at  Niajrara,  Albany,  N.  Y.,  18!l(t,  p.  (iO.  Rei)rinte(l  in  Ann.  Kep.  Smitli- 
Bonian  Institution,  IHlti),  pp.  '.i;>l~2-">7. 

*  "Sketch  of  the  Coastal  Toixijrrapliy  of  the  Xovtii  Sidi'  of  Lake  Superior,"  in  20tli  Ann 
Rep..  Minnesota,  Geol.  and  Nat.  Hist.  Surv.,  pp.  1S1-2S!). 


STUDIES   OF    SPECIAL   LACUSTRAL    HISTORY. 


101 


In  -iOtli  Ann 


ai)pi-oxiniately  pamllel  with  it.  Observations  on  the  amount  of  defoiina- 
tion  that  this  beach  has  suffered,  are  not  as  extended  as  coukl  be  desired, 
but  near  its  western  extension  there  is  evidence  of  a  cliange  of  level  of 
about  one  foot  per  mile. 

liecent  observations  by  F.  B.  Taylor'  in  the  legion  adjacent  to  Lake 
Superior  on  the  south,  have  shown  that  ancient  Ijeaches  may  be  clearly 
recognized  at  many  places  between  Duluth  and  Sault  Sainte  JNIarie.  The 
facts  recorded  by  Taylor  supplement  in  a  very  interesting  manner  the 
work  of  J^awson  on  the  nortliorn  side  of  the  same  basin,  although  fai-ther 
study  is  necessary  before  tlie  entire  history  of  the  great  predecessor  of  Lake 
Superior  can  be  Avrittcn.  At  the  south,  the  highest  beach  has  an  eleva- 
tion of  from  512  to  588  feet  above  Lake  Superior,  or  from  1014  to  1190 
feet  above  the  fea. 

Taylor  suggests  that  when  the  entire  outline  of  the  highest  beach  at 
the  north  shall  have  been  traced,  it  will  be  found  that  there  were  straits 
connecting  the  Superior  basin  with  that  of  Hudson  Bay.  This  Mould 
imply  a  submergence  of  a  very  large  portion  of  the  North  American  con- 
tinent to  a  depth  of  over  a  thousand  feet. 

The  erosion  produced  by  the  movement  of  ice  sheets  many  hundreds 
of  feet  thick,  over  the  Laurentian  basin,  modified  and  subdued  the  pre- 
vious relief,  and  tli>  ddbris  left  Avhen  the  ice  melted  covered  the  country 
witli  a  sheet  of  superficial  'leposits  to  such  a  depth  that  the  character 
of  the  underlying  hard-rock  topography  is  only  occasionally  revealed. 
The  depth  of  these  glacial  deposits  over  'reat  areas,  as  in  Micliigau 
and  Wisconsin,  is  from  one  to  two  hundred  feet,  but  is  probably  of  less 
average  thickness  in  Ohio  aiid  New  York.  All  pre-glacial  drainage  channels 
were  either  olistructed  or  obliterated  and  a  new  surface  given  to  the  land. 
The  drainage  was  thus  rejuvenated  and  is  still  innnature.  The  effects  of 
glacial  plantation  and  of  glacial  deposition,  in  forming  the  basins  of  tlie 
present  Laurentian  lakes,  has  been  pointed  out  in  discussing  the  origin  of 
lake  basins. 

In  this  brief  sketch  I  have  endeavored  to  show  that  the  history  of 
the  Laurentian  basin  includes  a  study  of  the  liard-rock  topography  as  it 
existed  previous  to  the  Glacial  epoch  ;  the  disturbances  and  changes  in 
drainage  i)roduced  by  the  ice  invasion  and  by  movements  of  elevation 
and  dejjression;  the  obstruction  of  the  ancient  waterways  by  glacial 
deposits  ;    and  the  origin  of  new  chainiels  of  d'ljcharge,  as  the  glaciei-s 

1  "  A  rcconnoissance  of  the  abandoned  shore  lines  of  the  .outh  coast  of  Lake  Sn])erior," 
in  Am.  Geol.,  Vol.  13,  1894,  pp.  305-383.     8ee  also  more  recent  papers  in  the  same  journaL 


102 


LAKES   OF   NOUTH    AMKUICA. 


; 


passed  away,  —  all  of  these  links  in  the  ooniplex  history  have  not  been 
completely  worked  out,  and  this  attractive  Held  is  still  open  to  the  geolo- 
gist and  geographer. 

In  conclusion,  it  is  Imt  t'air  to  state  that  while  the  liistorv  of  tlie 
Laurentian  basin  outlined  above  will,  I  believe,  be  accepted  as  in  tlie 
main  correct  by  most  geologists  of  the  United  States,  whose  attention  has 
been  directed  to  the  subject,  it  is  widely  at  variance  witli  the  coiudusions 
of  at  least  two  Canadian  geologists.  Sir  .1.  William  Dawson  maintains,  if  I 
understand  his  hyi)othesis  correctly,  that  the  sea,  laden  with  icebergs,  invaded 
the  Laurentian  basin  in  Pleistocene  times,  and  that  the  ii">rainesand  other 
deposits  occurring  in  it  aiul  over  a  wide  extent  of  adjacent  country,  and 
believed  by  most  observers  to  l)e  of  glacial  origin,  are  shore  accumulations, 
and  that  icebergs  and  floe-ice  played  an  important  part  in  their  formation. 

The  ancient  beaches  about  the  Laurentian  lakes,  while  considered  as 
true  shore  lines  by  S[)encer,  are  tliought  l)y  him  to  have  l)een  formed  at 
sea-level  durinsr  a  time  of  continental  submeruence,  and  that  the  ocean 
had  free  access  to  the  basin. 

It  may  be  that  in  these  summary  statements  I  do  injustice  to  the 
views  of  the  gentlemen  referred  to,  Ir.it  the  conclusions  indicated  are  so 
widely  at  variance  with  a  vast  body  of  consistent  evidence  gathered  by  a 
score  or  more  of  skilled  observers,  and  is  so  directly  <)p[)osed  to  my  own 
observations,  both  of  living  glaciers  and  of  the  records  of  past  glaciation, 
that  they  (h)  not  seem  at  present  to  l)e  open  to  protital)le  discussion. 

A  subsidence  of  the  eastern  border  of  the  continent  during  the  later 
stages  of  the  Glacial  e[)och,  or  following  its  close,  throughout  a  belt 
widening  from  New  York  city  northward,  and  including  the  valley  of 
Lake  Champlain,  is  well  known.  When  the  studies  leading  to  this  con- 
clusion are  extended  to  the  basins  of  the  Laurentian  lakes,  however,  not 
only  is  there  an  absence  of  salt-water  shells  and  other  evidences  of  marine 
occupation,  but,  seemingly,  positive  evidence  of  lacustral  condition. 

The  region  to  the  north  of  Lake  Superior  has  not  been  sufficiently 
studied  to  admit  of  an  opinion  being  reached  in  reference  to  the  questions 
just  considered,  from  the  records  there  obtained.  It  may  be  found  that 
the  highest  shore-line  in  the  Superior  basin  was  formed  by  a  water  body 
in  direct  communication  with  the  sea  to  the  north,  as  suggested  by 
Taylor.  Should  this  hypothesis  be  sustained,  it  would  add  an  interesting 
cliapter  to  the  history  of  the  Superior  basin,  and  render  a  review  desirable 
of  the  evidence  of  a  similar  nature  in  the  eastern  portion  of  the  region 
now  drained  by  the  St.  Lawrence. 


not  l)0('n 
the  geolo- 


iiy  of  tlic 
us  in  tlie 
Mition  has 
^nt'lusions 
itains,  if  1 
fs,  invaded 
1  and  other 
Antrv,  and 
imdations, 
t'oiiuation. 
side  red  as 
formed  at 
the  ocean 

ice  to  the 
ted  are  so 
liered  by  a 
o  my  own 
sjfhiciation, 
lion. 

-•  the  hater 
ut  a  belt 
valley  of 
)  this  con- 
vever,  not 
of  marine 
on. 

ifhciently 
(^nestions 
nnd  that 
ater  body 
ested  by 
iterestini^f 
desirable 
le  region 


STUDIES   OF 

SPKCIAL    LACUSTKAL 

HISTOltV. 

lua 

»- 

The  views  of  Dawson 

and  Spencer  are  set 

forth   in  the 

pub 

lications 

mentioned  in  the  following 

footnote,'  nnd  shou 

(1  be  attentively 

studied 

by 

all  who  undertake  to  re 

id  the  history  of  the 

Laurentian 

basins   from 

the 

original  records  in  order  that  their  conclusions  may  be  fairly  tested. 

Lake  Agassiz. 

At  the  tinu'  the  remarkable  changes  described  above  were  taking  place 
in  the  i^aurcntian  l)asin,  there  were  corresoonding  revolutions  in  the 
geogra[)hy  of  the  region  to  the  northwest  whii'h  now  drains  to  Lake 
Winncpeg  and  thence  through  Nelson  river  to  Hudson  l)ay. 

It  will  \h'  ri'adily  seen  on  glancing  at  a  niaj)  of  Canada,  that  if  a 
glacier  of  the  i-oiitinental  type  should  advance  southward  from  the  Hud- 
son bay  region,  the  drainage  would  be  obstructed  ami  a  lake  formed  over 
the  country  of  mild  relief  surrounding  Lake  \Viinie[)eg  and  the  Lake  of 
the  Woods,  and  extending  southward  through  the  Ked  i{iv(  r  valley,  far 
into  Minnesota.  Such  a  lake  would  discharge  southward,  and  contribute 
its  surplus  waters  to  the  ^Iississii)})i.  Should  the  hypothetical  glacier  re- 
ferred to  advance  until  it  occupied  all  of  the  Winncpeg  basin,  the  lake 
about  its  southern  margin  woukl  be  obliterated,  and  there  would  be  free 
drainage  to  the  Gulf  of  Mexico.  Shouhl  the  glaciei-  then  retreat  to  the 
north  of  the  divide  now  se}mrating  the  waters  flowing  southward  to  the 
Gulf  of  ^Mexico  from  those  flowing  northward  to  Hudson  bay,  a  lake  would 
be  born  about  tlie  margin  of  the  ice,  and  would  incres":.e  northward  as  the 
ice  retreated.  When  a  channel  leading  northward  was  uncovered  and 
rendered  available  as  an  outlet  for  the  lake,  the  ponded  waters  would  have 
their  level  lowered  and  their  area  contracted. 

The  study  of  the  Pleistocene  records  in  the  Red  Kiver  valley  and 
thence  northward  in  ^Lanitoba,  has  shown  that  changes  very  similar  to 
those  postulated  above  actually  occurred. 

The  evidence  of  the  former  existence  of  a  large  lake  in  the  Red  River 
valley  was  observed  as  far  back  as  1823  by  Keating,  the  geologist  of  the 
first  scientific  expedition  to  that  region.  Subse(pient  contributions  to  this 
investigation    have    l)een    made    by   several    observers,    and    notably    by 

J  J.  W.  Dawson,  "The  Canadian  Ice  Afje,"  Montreal,  lS!i:>;  .J.  W.  Spencer,  " Tlic  De- 
formation of  InKjuois  Beach  and  Birtli  of  Lake  Ontario,"  in  Am.  .lour.  Sci.,  .ser.  ;!,  vul.  -lO, 
18iH»,  pp.  44;]-4.")l  ;  J.  W.  Spencer,  "Deformation  of  tlie  Algon(|uin  Reach  and  tlie  Birth  of 
Lake  Huron,"  in  Am.  .Jour.  Sci.,  ser.  H,  vol.  41,  18!H,  pp.  12-21;  .T.  W.  Spencer,  "I'osi- 
I'leistocene  Subsidence  versus  Glacial  Dams,"  in  (ieol.  Soc.  Am.  Bull.,  vol.  2,  18!(1,  pp. 
4O0-474. 


104 


LAKES   OF   NORTH   AxMEUICA. 


fn 


Gen.  G.  K.  Warren,  who  first  explained  the  origin  of  the  valley  now 
occupied  by  Lake  Travei-se,  liig  Stone  lake,  and  the  Minnesota  river,  by 
showing  tliat  it  was  excavated  by  a  stream  flowing  to  the  Mississippi 
from  a  former  lake  to  tlie  north.  This  ancient  river,  whose  sonrce  has 
long  since  been  sapped  l)y  northward  drainage,  has  been  named  lliver 
Warren,  after  its  discoverer. 

The  great  lake  that  formerly  flooded  the  Winnepeg  basin,  and  dnring 
its  highest  stage  overflowed  through  River  Warren,  has  been  named  Lake 
Agassiz,  by  Warren  Upham,  in  honor  of  Louis  Agassiz,  Practically  all 
of  the  facts  and  conclusions  here  presented  concerning  tlie  history  of  that 
remarkable  lake,  have  been  made  known  through  the  long-continued  and 
skillful  investigations  of  Upham,  under  the  auspices,  at  different  times, 
of  the  geological  surveys  of  Minnesota,  the  United  States,  and  Canada,^ 
respectively. 

The  Red  River  of  the  North  rises  in  the  western  part  of  Minnesota, 
and  receives  the  tribute  of  Lake  Traverse,  situated  on  the  Minnesota- 
Dakota  boundary,  and  at  the  southern  limit  of  the  country  formerly 
flooded  by  Lake  Agassiz.  From  Lake  Travei"se  the  present  drainage  is 
northward  through  narrow  channels  sunken  in  the  sediments  of  the 
former  lake.  Between  the  streams  there  are  broad,  nearly  level,  inter- 
stream  spaces,  forming  typical  examples  of  new-land  areas,  on  which 
shallow  ponds  form  during  rainy  seasons.  About  the  borders  of  this 
broad,  level  extent  of  prairie  land,  now  transformed  into  wheat  fields, 
there  are  gravel  ridges  which  mark  the  surface  level  of  the  former  lake  at 
various  stages.  These  ancient  beaches  have  been  traced  northward  and 
found  to  diverge  toward  tl»e  northeast  and  northwest  when  the  central 
area  of  the  old  lake  was  approached,  and  have  been  mapped  so  as  to  show 
approximately  the  extent  of  the  water  body  that  built  them.  By  patiently 
following  these  ancient  shore-lines,  it  has  been  demonstrated  that  Lake 
Agassiz  covered  a  region  about  110,000  square  miles  in  area.  Its 
diameter  from  north  to  south  was  G75  miles,  and  from  east  to  west,  in  the 
wider  portions,  varied  frqm  225  to  300  miles.  It  was  the  largest  of  the 
Pleistocene  lakes  of  North  America  thus  far  discovered,  and  exceeded  the 
combined  areas  of  the  present  Laurentian  lakes.  The  rim  of  its  hydro- 
graphic  basin  embraced  a  region  not  less  than  half  a  million  square  miles  in 
area.     At  the  site  of  Lake  Winnepeg  the  ancient  lake  was  090  feet  deep. 


1  A  report  on  these  investigations  appeared  in  the  Geol.  and  Nat.  Hist.  Survey  of  Canada, 
Ann.  Kep.,  vol.  4,  1888-i),  pp.  1-160  E,  and  a  monograph  on  the  same  subject  is  soon  to  be 
issued  by  the  U.  S.  Geol.  Survey. 


STUDIES    OV   SPECIAL   LACIJSTHAL    HISTOKY. 


105 


One  of  the  most  interesting  discoveiios  in  eonneetion  with  tlie  beaches 
of  Lake  Agassiz,  is  that  they  are  no  h)nger  hcn-izontal,  and  besides  do  not 
lie  in  phiins  tliat  are  parallel  one  with  another.  TIk;  highest  water  line 
when  followed  nt)rtlnvard  has  been  found  to  rise  at  the  rate  of  200  feet  in 
300  miles.  There  are  five  beaches  that  are  especially  })rominent  and 
mark  a  lingering  of  the  lake  surface  at  their  respective  horizons.  The 
higlu!st  of  the  series,  known  as  the  Herman  beach,  when  traced  northward 
from  the  southern  end  of  the  Ked  Kiver  valley,  has  been  found  to  divide 
into  several  ))eaches  at  different  levels;  the  vertical  intervals  between  the 
division  imaeasing  northward.  The  meaning  of  this  fact  seem.s  to  be  that 
the  land  was  rising  at  the  north  at  the  time  the  beaches  were  formed  and 
at  the  same  time  the  surface  of  the  lake  was  lowered  by  reason  of  the 
opening  of  new  outlets. 

To  the  north  of  Lake  Winnepeg  the  higher  of  the  ancient  beaches  are 
absent  and  the  lower  ones  difficult  to  trace.  The  countiy  still  farther 
toward  Hudson  bay  is  low  and  does  not  present  a  barrier  that  under  any 
plausible  hypothesis  could  have  been  made  to  act  as  a  dam  to  retain  the 
waters  of  Lake  Agassiz.  What  then  could  for  a  time  have  reversed  tiie 
drainage  and  led  to  the  formation  of  a  lake  over  a  hundred  thousand 
square  miles  in  area? 

The  origin  of  Lake  Agassiz  as  explained  by  Upham,  is  in  harmony 
Avith  the  history  of  the  former  lakes  of  the  Laurentian  basin.  It  is  su})- 
posed  to  have  owed  its  origin  to  the  presence  of  a  vast  ice  sheet  over  the 
Hudson  bay  region  which  dammed  the  northward  drainage  of  the  Winne- 
peg basin  and  caused  the  waters  to  rise  until  an  outlet  was  found  at  the 
south  and  River  Warren  began  to  flow.  When  the  ice  retreated,  new 
outlets  at  lower  levels  became  available  at  the  north  and  the  waters  fell, 
but  lingered  for  a  time  at  the  horizon  of  each  of  the  various  beaches  that 
have  been  referred  to,  at  lower  levels  than  the  Herman  beach. 

There  are  facts  in  connection  with  the  ancient  floods  of  the  Laui-entian 
and  Winnepeg  basins,  which  seem  to  indicate  that  the  weight  of  the  ice 
during  the  Glacial  epoch  caused  the  land  to  subside,  and  that  when  the 
ice  melted  an  upward  movement  was  initiated.  Tliese  movements,  and 
also  the  attraction  of  the  ice  body  to  the  north  of  I^ake  Agassiz,  have 
been  thought  to  explain  the  gradual  rise  of  the  ])eaches  when  traced 
northward. 

The  strange  transformation  that  the  Winnepeg  basin  underwent  in 
Pleistocene  times,  leads  one  to  wonder  if  in  the  region  now  drained  hj' 
Mackenzie  river,  and  occupied  in  part  by  Great  Slave  and  Great  Hear 


!1 1 


lOG 


LAKES    OF    N'OKTH    AMKUICA. 


lakes,  there  may  not  be  equally  wonderful  records  awaiting  the  coming  of 
the  patient  in(iuirer. 


ht^;' 


Pleistocp:ne  Lakes  of  tffe  Ctueat  Basin. 

Diu'ino-  the  time  of  great  elimatic  changes  that  witnessed  the  birth, 
growth,  and  decadence  of  the  great  lakes  of  the  Jy.airentian  and  Winiiepeg 
basins,  described  above,  e(inally  important  tluctnations  occurred  in  tlie 
lakes  of  the  Arid  region.  Many  of  the  valleys  of  Utah  and  Nevada,  and 
of  adjacent  areas  both  north  and  south,  that  are  now  parched  and  desert- 
like throughout  the  year,  were  then  Hooded,  and  in  some  instances  tilled 
to  the  brim  so  as  to  overflow.  All  of  the  enclosed  lakes  west  of  the  Uocky 
mountains  were  then  of  greater  size  than  at  present  and  underwent  marked 
changes  in  sympathy  with  the  advance  and  retreat  of  glaciers  on  neighbor- 
ing mountains,  and  had  their  oscillations  controlled  by  the  same  causes, 
viz.,  variations  in  i)recipitation,  evaporation,  and  temperature. 

Of  these  numerous  water  bodies  there  were  two  of  broad  extent  Avhich 
may  be  taken  as  types  of  their  class  and  will  serve  to  give  an  epitome  of 
the  history  of  their  time.  The  two  ancient  lakes  referred  to  are  IJonnc- 
ville  and  Jiahontan*  aiul  are  represented  on  the  map  forming  Plate  19. 

Lake  IJonneville  was  named  by  (iilbert  in  honor  of  Cap'ain  B.  \j,  K. 
Bonneville,  U.S.vV.,  who  made  a  bold  explorarion  iut(^  the  wilds  of  the 
Rocky  mountains  in  1833,  and  was  the  first  person  to  gather  reliable 
information  concerning  the  region  formerly  occupied  by  the  great  lake 
now  bearing  his  name.  The  reader  will  perhaps  liave  an  additional 
interest  in  the  following  sketch,  when  he  recalls  the  "Adventures  of 
Captain  Bonneville,"  so  graphically  described  by  Washington  Irving. 

Lake  Lahontan  first  received  definite  recognition  in  ihe  re})orts  of  the 
40th  Parallel  survey  luuler  the  direction  of  Clarence  King,  and  was  named 
after  Baron  LaHontan,  one  of  the  early  explorei-s  of  the  Mississippi  valley. 
Why  LaHontan's  name  should  have  been  thus  connected  with  a  region 
more  than  a  thousand  miles  beyond  his  farthest  camp,  in  preference  to 
the  names  of  men  who  boldly  crossed  and  recrossed  the  land  referred  to 
when  it  was  a  trackless  desert  infested  wi*h  roving  bands  of  savages,  I 
must  leave  to  others  to  explain. 

As  siiown  on  the  accompanying  map,  Plate  19,  Lake  Bonneville  occu- 
pied viie  basin  in  which  Great  Salt   lake  now  lies,  on  the  east  side  of  the 

1  Clarence  King,  U.  S.  Geol.  Exploration  of  the  40th  Parallel.  Vol.  1, 1878,  pp.  400-520. 
—  G.  K.  Gilbert,  "Lake  Bonneville."  U.S.  Geol.  Surv.,  Monograph  No.  1,  1890.  -L  C. 
Rns.sell,  "  Lake  Lahontan."     U.  S.  Geol.  Surv.,  Monograph  No.  11,  188.'>. 


)  coming  of 


^AKKs  OK  N,„frii  Amkhi,  A. 


rr-ATK  i!). 


the  bivtli, 
Wiiuu'pcu- 
■red  in  the 
evada,  and 
and  dt'sert- 
mces  HIIimI 
tlie  Rocky 
:;nt  inark('(l 

I  neiji'hljoi- 
uie  causes, 

tent  wliicli 
epitome  of 
ire  Bonne- 
late  19. 

II  n.  L.  E. 
lids  of  tlie 
er  reliable 
^reat  lake 
additional 
sutures  of 
rving. 
arts  of  the 
vas  named 
ppi  valley. 
Ii  a  region 
ference  to 
eferred  to 
savages,  I 

viWe  occu- 
ide  of  tiic 

pp.  490-520. 
890.  -  I.  C. 


i, 


STl'DIKS    OK    SPKCIAL    LACUKTItAL    MISTOnv. 


107 


Great  Masiii,  while  Lake  Laluuitaii  Hooded  a  st-russ  of  irn-'pfular  valleys  on 
the  west  shhi  of  the  saiDt;  jri-eat  area  of  interior  (h'aiiiaf,^'  and  is  now  repre- 
senti'd  hy  Pyramid,  W'innennicea,  Walki'r,  Cai-son,  iind  IIinnl)ohlt  hikes, 
Nevachi,  and  hy  Honey  hike,  California. 

These  two  ancient  lakes  were  eonteniporaries,  and,  althon<,di  differinpf 
in  their  histories,  ])ear  similar  testimony  in   reference,  to  cdimatii'  chanifcs 


and 


.tl 


sni>i»lement  t'ach   others    records    in  a    reiii;nkal)l»!   maiinei 


ikal)h 


'II 


leir 

hydronrii[)hic  hasins  joined  each  other  in  noi  lii-easlern  Nevada,  for  a 
distance  of  abont  twenty-live  miles,  and  toj^ether  occupiiMl  the  entire 
width  of  till-  (Jreat  IJasin.  Lake  Uonneville  received  its  water  supply 
from  the  Wasatch  and  I'inta  monntains,  then  snitw-clad  thron<,di(»nt  the 
year  and  hoklinj^  glaciers  of  the  Ali»ine  type  in  many  of  their  valleys. 
Several  of  the  ice  streams  on  the  precipitons  western  slope  of  tin;  Wasatch 
monalains  reached  nearly  to  the  ancient  lake  which  washed  the  hase  of 
the  range,  and  one  of  them  was  prolonged  for  a  short  distance  into  its 
■waters.  Lake  Lahontan  derived  its  principal  water  su[tply  from  the  Siena 
Kevada,  which  formed  the  western  rim  of  its  drainage  basin  for  a  distance 
of  250  miles,  and,  like  the  eastern  borders  of  the  Honneville  basin,  was 
glacier-covered. 

liuke  Bonneville  at  the  time  of  its  niaximnin  extension  had  an  area  of 
19,7*)0  sipiare  miles,  and  a  hydrogiajdiic  basin  'tii.OOO  scjuare  miles  in 
area.  The  more  irreynlar  water  surface  of  J^ake  I^ahontan  was  8.4:22 
sipiare  miles  in  area,  and  occupied  the  lowest  depressions  in  a  hydro- 
graphic  basin  containing  40,7  7 '>  square  miles.  The  great  size  of  the 
hydrograi)hi(!  basins  of  these  lakes  in  comparison  with  their  extent  of 
water  surface,  is  a  noteworthy  feature.  The  ratio  of  the  extent  of  lake 
sui'face  to  area  of  hydrftgraphic  basin  in  the  case  of  Lake  Bonneville  was 
as  1  to  2.6,  and  in  the  case  of  Lake  Lahontan  about  1  to  5.  The  corre- 
sjjonding  ratios  in  the  basin  of  Lake  Sujjcrior  are  as  1  to  1.72;  and  for 
the  combined  Laurentian  lakes  as  1  to  8.11*.  The  small  extent  of  the 
ancient  lakes  of  the  Great  P>asin  in  comi)arison  with  the  areas  draining  to 
them,  more  especially  in  the  case  of  l^ake  Lahontan,  indicates  that  the 
climate  of  their  time  was  not  markedly  humid. 

The  maximum  de^jth  of  Lake  Bonneville  as  recorded  by  beach  lines 
on  the  mountain  forming  its  shores,  and  on  the  precipitous  islands  now 
rising  in  (treat  Salt  lake,  w'as  lOf)'^  feet.  Tlu^  greatest  dejith  of  l.,ake 
Lahontan  was  880  feet. 

The  most  striking  difference  in  connection  with  these  two  ancient 
seas  is  in  reference  to  overflow.     The   waters  of  Lake  Bonneville  rose 


I 


108 


LAKKS    OF    NOKTH    AMKUICA. 


until  they  found  an  outlet  and  escaped  through  a  elianiiel  leading  north- 
ward from  ('acJH'  valley,  in  I  tali  and  Itialio,  to,  Snake  river  and  thence  to 
the  ('nlniul)ia.  The  ontHowiniu;  sticani  at  its  source  crossed  incoherent 
alluvial  deposits  and  lapidly  cut  down  a  channel  of  disciiar^-e  to  a  depth 
of  870  feet,  thus  lowering,'  the  lake;  hy  that  amount.  I)urin<,'  this  episode; 
in  its  history  the  lake  was  fresh,  hut  at  later  stajjfes,  when  its  surface  fell 
helow  the  level  of  the  hottom  of  thtr  chainiel  of  dischar<j['e,  it  hecauu' 
saline.  The  watei-  sui>i>ly  of  Lake  I^ahontan  was  less  ahundant  and  it 
never  rose  so  as  to  liiul  an  (uitlet.  Its  waters  were  perhaps  hrackish 
duriufT  its  higher  stashes,  and  hecame  saline  and  alkaline  as  concc^ntration 
j)ro;^iessed. 

Kach  of  these  hdces  had  two  hififh-water  statues,  separated  hy  a  time  ol' 
low  water  and  prohahly  of  complete  desiccation.  The  second  hi<,di-water 
stage  in  each  instance  was  the  more  marked  of  the  two.  These  fluctua- 
tions  are  indicated  in  the  f(»llowing  dia<nam  of  the  rise  and  fall  of  Lake 
Lahontan. 

Each  lake  spread  out  two  sheets  of  line,  evenly-laminated  elays,  sepa- 


Fia 


•niAGRAM  .-ilOWINCi   TIIK  lUsE  AM)   FALL  OP  LAKE   I.AHONTAN. 


rated,  at  least  ahout  their  horders,  by  deposits  of  coarse  gravel  and  sand 
washed  in  from  the  adjacent  slopes  during  the  inter-lacustral  time  of  low- 
water. 

There  are  many  reasons  for  concluding  that  the  two  high-water  stages 
recorded  hy  beach  lines  and  by  sedimentary  deposits  in  the  basins  of  lakes 
lionneville  and  Lahontan,  correspond  in  time  with  two  of  the  periods  of 
glaciation  recoi'dcd  in  the  Lilurentian  basin.  Two  i)eriods  of  marked 
advance  separated  by  a  time  of  retreat,  are  also  indicated  by  the  glacial 
records  in  the  cafions  of  the  Sierra  Nevada. 

The  waters  of  both  Bonneville  and  Lahontan  underwent  many  minor 
fluctuations  of  level  as  is  the  rule  with  all  enclosed  lakes.  'J'he  terraces, 
embankments,  deltas,  etc.,  constructed  about  the  shores  of  Lake  Honne- 
ville  are  on  a  grander  scale  than  in  the  basin  of  its  companion  lake,  for 


P  f 


STl'IilKS    (IF    Sri-.<1AI,    I.ACl'STIJAL    lIlsTOItY. 


100 


nfj  tiorth- 

tllt'IlCf    to 

ii'.'idn'n'iit 
(»  a  (leptli 
is  e])isoiU' 
ufact"  It'll 
it  iK'CiUne 
lilt  and  it 
*  inackisli 
cent  nit  ion 

■  a  time  ol" 
hiy-li-watev 
!8e  ttuftna- 
vU  of  Lake 

ulays,  sepa- 


[l  and  sand 
inu'  ol"  low- 
later  staf;c»'*^ 
[us  of  lakes 

periods  of 
bf    marked 

the  glae.ial 

Lmy  minor 
lie  terraces, 
Ike  Honiie- 
|i  lake,  for 


the  reason  that  it  was  the  iiiiifei'  ol  tlif  two  water  hodies  and  had  a  more 
rej^idar  (Mitline.  tiins  .t-ivinjif  the  wind  a  hetti-r  opportnnity  to  act  on  its 
waters,  and  also  heeaiise  it  was  judd  at  a  delinite  level  I'oi'  a  loiijf  period, 
or  rose  to  the  same  horizon  at  varions  times,  on  aeconnt  of  its  havini; 


"K 


an 


outlet. 


The  hiyhest  water  line  ahont  Iiake  Bonneville,  named  the  "  llonneville 
heath,"  is  ctjuspienons  not  so  mneh  tin  aeetmnt  of  its  stren^4h  as  for  the 
reasttu  that  it  marks  the  dividing-  line  hetv.'een  rain  senlptrire  on  the 
hi^hei'  poititms  of  the  horderint>' mountains  and  the  eharaeteristie  ttipojfia- 
phy  due  to  tlie  wmk  of  waves  anil  eurri'iits  on  theii'  Ittwfr  slopes.  'I'he 
■lianntd  of  ilis('har<>'e 


lowt'ifil   until  a  sill  tif  resistant   liineston 


enannei  oi  ins('nar<,M'  was  lowfreii  unui  a  siii  tn  resistant  limestone  was 
reaehed  wliieh  determined  the  httri/.on  of  the  strongest  and  hest  devtdttpetl 
terraces  and  emhaidvinents  in  the  hasin.  A  well  detined  heaeh  at  this 
htui/.on  is  knt)wn  as  the  "  Pi'ovt)  heach."  the  name  In  iny  dcrivetl  from  the 
ttiwn  tif  l*ri>vt),  Utah,  which  stantls  on  a  hroad  delta  ftirmed  hy  the  sedi- 
ment of  l*rovo  river,  when  the  lake  stt»od  at  the  hori/.tm  of  its  h)West 
point  of  (lischar<,'e.  The  waved)uilt  sti'uetures  inarkin<f  the  I'rovo  sta^c 
are  on  a  niagnilicent  scale  and  are  still  almost  as  fresh  in  api)earanee  and 
perfect  in  l't>rm  as  if  al)an(h)ned  hy  the  waves  hnt  yesterday.  In  the 
Lahontan  hasin  the  shore  tt>i)Ot>iapliy  was  never  stroiififly  j)roiiounced. 
Flnctnatitnis  i>f  level  were  not  controlled  hy  an  ontlet,  and  the  nnnicrons 
islands  and  heatUands  diminished  the  intlnence  of  the  wintl  and  checked 
the  action  of  waves  and  cnrreiits. 

The  chemical  histories  of  lakes  IJonneville  and  Lahontan  are  fully  as 
instructive  and  of  as  crreat  interest  as  their  physical  chanj>es.  In  this 
connection,  the  liasin  of  Lake  Lahontan  has  heen  ftminl  to  exceed  its 
comi)anion  in  the  completeness  of  its  records.  The  escape  of  the  waters 
of  Lake  Bonneville  insured  its  freshness  dnrint''  a  part  of  its  history.  The 
ahsence  of  an  outlet  for  the  waters  of  Lake  Lahontan  led  to  a  hii>h  def^ree 
of  concentratit)!!. 

When  lake  waters  arc  coiK^entraved  hy  evaporation  the  lirst  snhstance 
to  be  precii)itated,  as  previously  described,  is  calcinm  carbonate.  About 
the  shores  of  Lake  Bonneville  there  are  in  favorable  Itu-alities,  consider- 
able deposits  of  this  stibstance  in  the  form  of  coral-like  incrustations 
known  as  calcareous  tufa.  It  appears  on  rocky  points  and  forms  a  cement 
for  gravel  and  sand  on  the  outer  borders  of  some  of  the  terraces,  but  is 
insignificant  in  amottnt  and  simple  in  character,  when  compared  with 
the  truly  immense  accumulations  of  a  similar  nature  in  the  Lahontan 
basin. 


110 


LAKKS   OF    NORTH    AMKUICA. 


!!.'■'     vi 


Tlu'  pivc'ii»itati()ii  of  caleium  carbonate  ffom  l;ikc  waters  takes  place 
priiudpally  in  two  ways:  it  may  separate  in  tlie  opiMi  lake  and  tall  to  the 
bottom  in  a  finely  divided  state  and  become  mingled  with  mecliaidcal 
sediments  so  as  to  form  marls,  oi'  it  may  be  }>reci[)itaied  where  solid 
rocks  occnr  and  cover  them  with  a  dense  incrnstation.  The  ability  of 
ordinary  snrface  waters  to  dissolve  ealcinm  carbonate,  dejiends  maiidy  on 
the  carbonic  acid  gas  they  hold  in  solution.  Lake  waters  lose  their  dis- 
solved gases  most  rapidly  whi're  they  form  breakers  along  the  shore,  as  in 
such  instances  they  are  most  thoroughly  aerated.  For  this  I'eason,  the 
bohU'st  headlands  are  apt  to  receive  the  heaviest  deposits  of  tufa  when  the 
waters  dashed  against  them  became  concentrated.  It  is  at  such  ^)calities 
that  the  princi[)al  deposits  of  tufa  in  the  lionneville  basin  occur.  It 
ha[ti)ens  also  that  calcium  carbonate  has  a  tendency  to  accumulate  about 
solid  bodies,  not  only  because  they  afford  a  stable  supjuu-t,  but  for  the 
additional  reason  that  points  and  angles  indm-e  crystallization.  Calcareous 
tufa  was  deposited  in  vast  (piantities  about  the  shores  of  Lake  Lahontan 
Avhei'ever  there  were  rocky  slopes  and  in  increasing  abundance  from  an 
horizon  high  iip  on  its  borders  down  to  the  deepest  point  now  exposed. 
The  fluctuations  of  level  in  Lake  Bonneville  Avere  rec^orded  principally  by 
beaches  and  embankments  of  mechanical  origin  :  similar  changes  in  Lake 
liahontiiU  arc  made  known  by  tuf.t  deposits  of  chenucal  origin. 

The  tufa  of  the  J^ahontan  basin  i)resents  three  main  varieties,  each  of 
which  is  composed  of  concentric  layers  as  is  shown  in  Plate  21.  The 
smallisr  divisions  seem  to  indicate  minor  changes  in  the  chemistry,  an<l 
perhaps  also  fluctuations  in  the  temperature,  of  the  water  from  which  tlu'v 
were  precipitated.  The  three  })rincipal  varieties  have  been  named  in  the 
order  of  their  formation,  Lithoid,  T'hinolitic,  and  Dendritic  tufa.  Lithoid 
tufa  is  a  compact  stony  substance  with  a  granular  texture  :  Dendritic  tufa 
has  an  i»[)en  structure  and  resembles  a  mass  of  branching  twigs  turned  to 
stone;  and  Thinolitic  tufa,  shown  in  Plate  22,  is  com})osc(l  of  avcII 
defined  crystals  U.  which  the  name  Thinolite  Avas  given  by  Clarence 
King.  The  composition  of  each  of  these  varieties  is  the  same.  They  are 
comj)osed  of  calcium  carbonate  with  usually. some  slight  amount  of  im- 
jturities.  Their  Avide  variation  in  structure  and  general  a[)[)e{irance,  is 
due  to  diffe'XMiees  in  the  condition  of  tlu?  laki'  waters  at  the  time  of 
their  formation.  _    _-  - 

About  Pyramid  lake,  Avhere  the  Lahontan  tufas  aic  usually  Avell  dis- 
played, the  first  or  Litlioid  variety  reaches  a  height  of  oOO  feet,  tlu?  Thiiuv 
litic   110    feet,  and   the   third   or  Derulritic   varietv,   B20  feet  above  the 


Lakes  of  Nohtii  America. 


Plate  20. 


TUFA   TOWERS    ON    THE    SHORE    OF    PYRAMID    LAKE,    NEVADA. 


i 
i 
t 
ii 

V 

1 

-I: 

w 

fr, 

a  ( 

wl 

mt 

its 

aiK 

eor 

ma 


STUDIES   OF    SPECIAL    LACUSTUAL   HISTOKY. 


Ill 


surface  of  the  present  lake.     Tlie  relation  of  the   tufa  deposits  and  the 
terraces  with  which  they  are  tissociated,  are  shown  in  the  iollowing  diagram. 


Lahontan  Beach Kilt  feet. 

Litlioid  Terrace WW    " 

Dendritic  Terrace ;i2<)    " 

Thinolitic  Terrace 110     " 

Surface  of  I'yramid  Lake,  1882    .    ,       0    " 


Fig.  9.  —  Diaobam  bhowino  the  relation  of  the  Terraces  of  Lake  Lahontan 

TO  Pyramid  Lake. 

The  Lithoid  tufa  near  its  upper  limit  is  seldom  over  eight  or  ten 
inches  thick,  but  increases  to  ten  or  twelve  feet  on  the  lowei;  slopes.  The 
Thinolite  is  usually  from  six  to  twelve  feet  thick.  The  Dendritic  variety 
is  the  heaviest  of  all  and  frequently  appears  on  steep  slopes  in  imbricated 
layers  from  fifty  to  sixty  feet  thick.  In  some  favorable  locality  the  entire 
tufa  deposits  have  a  thickness  of  at  least  eighty  feet,  and  in  rare  places 
near  tlie  surface  of  Pyramid  lake  and  partially  concealed  by  its  waters, 
there  is  evidence  that  these  deposits  are  still  more  massive.  The  total 
amount  of  calcium  carl)onate  deposited  from  the  ancient  lake  can  only  ))e 
estimated  in  millions,  if  not  billions  of  tons. 

Every  island  and  rocky  crag  that  rose  in  Lake  Lahontan  becnme  a  cen- 
ter of  ^accumulation  for  tufa  deposits  and  was  transformed  into  strange  and 
fre(iueni'\'  fantastic  shapes  by  the  material  precipitated  upon  it.  Now 
that  the  waters  of  the  ancient  sea  have  disappeared,  these  structures  stand 
in  the  desert  valleys  like  the  crumbling  ruins  of  towers,  castles,  domes,  and 
various  other  shapes,  in  keeping  with  the  desolation  surrounding  tliem. 
The  finest  examples  of  these  water-built  structures,  some  of  them  a  hun- 
dred feet  or  more  in  ht'ght,  occur  about  the  border  of  Pyramid  and 
Winnemucca  lakes  (Plate  20),  or  rising  from  tlieir  l>ottoms  and  still 
wholly  or  in  part  submerged.  The  islands  in  Pyramid  lake  are  sheatlied 
from  base  to  summit  with  tliese  deposits  and  their  precnpitous  sides  g-ven 
a  convex  outline,  owing  especially  to  the  vast  de})osit8  of  Dendriiic  tufa, 
which  was  precipitated  most  abundantly  midway  uj)  the  slopes.  The 
most  remarkable  of  these  islands,  and  the  one  fiom  which  the  lake  derives 
its  name,  is  shown  in  the  sketch  forming  Plate  23.  When  the  uifa  towel's 
and  castle-like  piles  are  broken,  the  concentric  layers  of  which  they  are 
composed  are  revealed  and  fill  one  with  wonder  at  the  vast  imoiint  of 
material  they  contain,  as  well  an  attract  the  eye  on  account  of  the  flelicacy 


11:> 


LAKKS    OF    NOItTH    AMERICA. 


:   It 

ill 


and  boiuity  of  tln'ir  striu'tuii'.  Xowlicii'  t'lsc  in  this  country,  and  so  far 
us  ii'i)ort('(l,  nonlion*  else  in  tlic  world,  are  roeks  formed  of  preeipitates 
from  lake  wateis  so  maj^nilieenlly  displayed  as  in  tin;  desert  valleys  of 
Mevada. 

The  fascination  of  the  weird  and  frecpiently  wonderfully  impressive 
sceneiy  of  the  rejrion  formerly  suhmern't'd  beneath  the  waters  of  Lake 
Lahontan,  is  enhanced,  at  least  to  the  jreolojiist,  by  the  fact  that  there  is 
yet  an  unsolved  mystery  eonneeted  with  the  tufa  deposits  that  start  out 
as  strano'e,  ^iountic  forms  from  the  desert  haze,  as  one  slowly  traverses 
those  bitter,  alkaline  lands. 

It  is  believed  that  we  understand  how  the  more  compact  and  stone- 
like variety  of  tufa  was  deposited,  since  similar  accutnulations  are  formeil 
where  waters  saturated  with  calcium  cmbonate  deposit  that  salt  on  account 
of  the  loss  of  carbonie  acid.  The  Dendritic  tufa  may  also  have  been  pre- 
ei[)itated  in  a  similar  manner,  or  perhaps  through  the  ageuey  of  low  forms 
of  [dant  life.  The  mode  of  origin  of  the  tufa  with  well-detined  crystals, 
howcvei',  is  still  unknown,  although  both  geol(\gists  and  chemists  have 
sought  diligently  to  discover  tha  secret  of  its  formation.  The  oi)en  cellu- 
lar structure  of  the  crystals,  as  well  as  their  fcu'ms,  suggest  that  they  aiv 
l)seudomor[)hs,  that  is,  having  a  false  form,  or  a  form  not  assumed  by  cal- 
cium carbonate  on  crystallizing,  but  resulting  from  the  iilteration  or 
replacement  of  some  other  mineral.  This  suggestion  only  removes  the 
dilUculty  tme  step  farther,  however,  since  the  nature  of  *he  original  min- 
eral is  still  unknown.  A  more  detinite  statement  of  t'lis  problem  may  be 
found  in  a  special  repo)'t  on  Thinolite,  by  E.  S.  Dima,  who  has  [)ut  the 
matter  in  a  (dearer  light  than  had  [)reviously  been  d.)ne.^ 

One  of  the  most  I'cmarkable  facts  in  connection  with  the  history  of  the 
Lahontan  basin,  is  that  the  present  lakes  within  it,  which  might  be  sup- 
posed to  be  renmants  of  the  ancient  water-body  left  by  inconiidete  evap- 
oration, and  th:'refore  intensely  saline,  are  in  reality  scarcely  more  thiui 
brackish.  As  shown  ii  the  table  of  analyses  of  saline  lakes  given  on 
page  7:2.  i'yramid,  Winnenuicca,  and  Walker  lakes,  the  representative 
water  boilies  now  existing  in  the  Lahontan  basin,  carry  oidy  a  small  frac- 
tion of  one  per  cent  of  saline  matter  in  solution.  We  know  that  Lake 
Lahontan  did  not  overllow.  All  of  the  saline  matter  carried  into  it, 
therefore,  nuist  still  be  retained  in  its  basin.  The  vast  quantity  of  vari- 
ous salts,  and  espet-ially  of  sodium  chloride,  sodium  sulphate,  and  sodium 


'  ■■  ("lystallogriiiilik'  Stiuly  of  the  Thinolite  of  Lake  Lahontan, "'  Bulletin  No.  12,  U.  S. 
Cleol.  Suivev. 


I  so  far 

lU'VS  of 

pressive 
)t'  Lake 
there  is 
tart  out 
vaverses 

tl  stoiie- 
!  formed 
account 
)eeu  pre- 
)W  forms 
crystals, 
ists  have 
HMi  eellu- 
they  are 
il  hy  eal- 
iilion   or 


(tves 


tl 


le 


liiial  min- 
II  may  1k' 


1 


lUt   tl 


le 


rv  o 


f  th 


t  1 


)0  s 


up 


'U'  evap- 
than 


lore 


i-iveii  on 
tentative 
iiall  frae- 


lia 


ivt' 


t   Lai 

into  it. 

of   vari- 

ll  sodium 


X 
■< 
X 


3 


1-'  i; 


lUilililc :. 


<o 


to 


t      O 

Q- 


LU 
> 
CO 

CO 

UJ 

O 

o 

CO 
O 

z 

o 

X 

CO 

<~ 

Q 
< 
> 

UJ 


CO 

O 

z 

cc 
a. 
CO 

CO 
z 


I- 
< 

< 

O 

< 

u. 
.3 

H 


Jiiililjiiiiiiiiiiiiillililiiii 


STUDIES    OF   SPECIAL   LACIJSTRAL    HISTORY. 


113 


carbonate  thus  concentrated,  is  indicated  by  the  weight  of  the  calcareous 
tufa  lining  the  basin.  In  onUnary  river  waters,  as  already  shown,  the 
calcium  carbonate  is  about  the  same  as  the  amount  of  all  other  salts  in 
solution.  It  follows,  therefore,  that  the  more  solnl)le  salts  contributed  to 
Lake  Lahontan  must  have  been  ec^ual  in  weight  to  the  tufa  deposits  just 
described.  Such  a  vast  quantity  of  saline  matter,  if  contained  in  the 
present  lakes,  would  make  them  ccnicentrated  brines.  The  (juestion  is, 
what  has  become  of  the  more  soluble  salts  contributed  to  the  waters  of  the 
ancient  sea  ? 

A  lake  may  occasionally  evaporate  to  dryness,  or  exist  as  a  playa  lake 
for  a  long  })eriod,  that  is,  expanding  during  rainy  seasons  and  becoming 
desiccated  either  during  dry  seasons,  or  occasionally  in  years  of  unusual 
aridity.  Under  such  conditions  its  contained  salts  would  be  precipitated 
and  become  buried  or  absorbed  by  mechanical  sediments,  so  that  when 
a  change  of  climate  permitted  the  existence  of  a  perennial  lake  in  the 
same  basin,  it  would  be  fresh,  or  essentially  so.  This  is  what  seems  to 
have  occurred  in  the  Lahontan  basin.  The  old  lake  was  probably  eva})or- 
ated  to  dryness  and  the  precipitated  salts  buried  beneath  phiya  chiys,  and 
when  a  change  to  slightly  more  humid  conditions  permitted  of  the  birtii 
of  the  i)resent  lakes,  a  new  cycle  was  begun. 

From  analyses  of  the  waters  flowing  into  the  present  lake  of  the 
Lahontan  basin,  it  has  been  estimated  that  under  existing  conditions  they 
would  acquire  their  present  degree  of  salinity  in  about  300  years.  It 
seems  to  follow  from  this  study  that  during  a  long  term  of  yeai-s,  ending 
about  300  years  ago,  the  climate  of  Nevada  was  so  intensely  arid  that  no 
pereiniial  lakes  could  exist  within  her  borders. 

An  account  of  the  physical  and  chemical  histories  of  the  ancient  hdces 
of  Utah  and  Nevada  should  be  followed  by  a  description  of  the  plants  and 
animals  that  found  a  home  on  their  shores,  but  unfortunately  our  informa- 
tion in  this  connection  is  vague. 

The  sediments  of  lakes  Bonneville  and  Lahontan,  unlike  many  other 
lake-beds,  are  extremely  poor  in  vegetable  fossils.  A^  the  conditions  for 
the  preservation  of  such  remains  were  favorable,  and  as  an  extended 
search  has  failed  to  unearth  so  much  as  a  single  leaf  or  a  single  water- 
logged tree-trunk  from  their  sediments,  it  may  reasonably  l)e  concluded 
that  their  shores  were  not  forested,  and  were  probably  even  more  barren 
and  desolate  than  at  the  present  day.  Thi«  result  cannot  be  considered 
as  surprising  in  A'iew  of  the  great  fluctuation  of  climate  that  the  Great 
Basin  experienced  in  Pleistocene  times. 


114 


LAKES   OF   NOHTH    AMEUICA. 


U'' 


Of  the  remains  of  vertebrates,  the  bones  of  the  mastodon  or  mammoth, 
and  f>f  the  ox,  camel,  and  horse  have  l)een  found  in  tlie  sediments  of  Lake 
Laliontan,  together  witli  a  single  undetermini  d  llsh.  The  bones  of  a 
nnisk-ox  were  obtained  nea»'  Salt  Lake  City  under  sueh  cdnditions  that  it 
is  believed  they  were  buried  in  the  upper  strata  of  the  lioniieville  sedi- 
ments. The  basins  of  e(intem[)oraneous  lakes  in  Oregon,  have  yielded 
vertebrate  fos.s.'ls  more  abundantly,  but  concerning  these  there  are  differ- 
ences of  oi)inion  as  to  their  age.  It  is  probable  that  some  of  them  at  least, 
aii<l  perhiti)s  tlic  larger  portion,  were  washed  out  of  oliler  deposits  and 
accumulated  in  tiie  l)asin  where  they  are  now  found. 

In  the  sediments  of  both  lioiineville  and  Lahontan  there  are  many 
species  of  fresh-water  shells,  but  these  are  usually  small  individuals,  and 
appear  to  have  lived  under  unccmgenial  conditions. 

The  remains  of  animal  life  do  not  seem  to  point  to  any  very  definite 
conclusion.  We  are  led  to  believe  from  all  of  the  evidence  available, 
however,  that  the  climate  of  the  hike  period  was  cold  and  changeable, 
and  eonse(piently  uncongenial  to  either  plant  or  animal  life.  The  inter- 
lacustral  epoch  wi  s  probably  a  time  of  high  temperature  aiul  aridity. 
The  large  animals  wUose  bones  have  been  discovered  may  have  been 
forced  to  migrate  owing  to  wide-reaching  climatic  changes,  and  were  per- 
liaps  only  temporary  visitors  to  the  region  where  they  succumbed  to  ad- 
vei-se  conditions. 

The  mastodon  and  mammoth  roamed  over  nearly  the  whole  of  North 
America  during  Pleistocene  times,  but  have  since  become  extinct.  The 
camel  is  no  longer  fourul  on  this  continent,  and  the  hoi-se  was  extinct 
before  the  coming  of  the  white  man.  The  mtisk-ox  is  now  found  only 
far  to  the  north.  The  extinction  of  some  of  these  large  animals,. and 
the  scattering  of  others  to  distant  regions,  suggests  the  lapse  of  a  long 
j)erio(l  of  time  since  they  lived  together  where  their  remains  are  now 
found,  and  also  points  to  great  changes  in  climatic  and  other  elements  of 
their  environment. 

Of  the  i)resence  of  man  on  the  shores  of  lakes  Bonneville  and  Lahon- 
ton  the  records  are  silent. 


Lakes  of  the  Remote  Past. 


The  presence  of  the  bones  of  large  animals  in  the  sediments  of  lakes 
Bonneville  and  Lahontan  naturally  leads  one  to  look  farther  back  in 
the  earth's    history,  to  the  dei)()sits  of    other    lakes   from  which    a  vast 


amniotli, 
i  of  Luke 
lies  of  11 
lis  tliat  it 
•ille  sedi- 
->  yielded 
ve  (liiYer- 
1  at  least, 
osits  and 

are  many 
luals,  and 

•y  definite 
available, 
langeable, 
The  iuter- 
d  avidity, 
lave  been 
were  per- 
bed  to  ad- 

of  North 
kct.  The 
lis  extinet 
pund  only 

mals, .  and 

of  a  long 
are  now 

iiuents  of 

Id  Lahon- 


8TUD1HS   OF    Sl'KCIAl.   LACUfSTHAL    HISTORY. 


116 


of  lakes 

back  in 

111    a  Vtiat 


menagerie  of  strange  and  fre<|Mently  gigantic  forms  have  been  made 
known  by  the  labors  of  American   j)aleiintologists. 

Innnediately  i»rece(nng  the  "(Jreat  (u'ological  Winter,"  as  the  (ilacial 
epoch  has  l)een  termed,  when  half  of  the  North  American  continent  was 
sheathed  in  ice,  there  was  a  pciiod  of  genial  dinuite  when  vegetation,  as 
varied  and  beantifnl  as  that  of  the  Mississippi  valley  to-day,  extended  far 
north  and  leached  the  vicinity  of  the  j>ole  itself.  I )nring  different  epochs 
in  this  geological  summer,  known  as  the  Tertiary  period,  vast  fresh-water 
hikes  existccl  in  the  Cordilleian  region,  several  of  which  were  fai-  more 
extensive  than  any  lakes  now  known.  In  some  of  these  vasi  inland  seas 
several  thousand  feet  of  sediments  were  laid  down.  In  these  deposits 
we  find  in  abundance  the  impressions  of  leaves  lliiil  wcic  blown  from  the 
land,  or  washed  in  by  tributary  streams,  and  the  boiu's  of  many  large 
mammals,  whose  homes  were  along  the  lake  shores  and  on  neighboring 
forest-covered  hills. 

All  trace  of  the  shore  tojjography  of  the  Tertiary  lakes  has  disa{)- 
peared,  and  in  many  instances  the  beds  of  sand,  clay,  and  volcanic  dust 
deposited  over  their  bottoms  have  been  upheaved  into  mountain  ranges, 
and  deeply  dissected  by  erosion.  Their  histories  can  only  be  deciphered 
from  the  records  in  their  sediments.  Their  story  <leals  largely  with  the 
structure,  habits,  and  develo})ment  of  vertebrate  animals,  and  must  be  left 
to  those  skilled  in  that  bi-anch  of  study. 

Beyond  the  Tertiary  period,  and  so  remote  from  our  own  time  that 
humble  forms  of  mammalian  life  had  only  just  ai)i)eaied  on  the  earth, 
were  the  Jurassic  and  Triassic  peiiods.  In  this  Mesozoic  time,  or  middle 
age  of  the  earth,  lakes  also  existed,  and  in  their  sediments  the  skeletons  of 
another  striking  and  grotesque  assemblage  of  strange  forms  were  pre- 
served. The  magic  wand  of  modern  science  has  brought  forth  from  these 
long-silent  tombs  a  wonderful  procession  of  gigantic  reptiles,  the  like  of 
which  has  not  since  existed  on  the  earth. 

Still  more  remote  were  the  lakes  and  swamps  of  the  Carboniferous 
2)eriod.  The  oldest  records  of  air-breathing  vertebrates  yet  discovered  are 
the  bones  of  reptiles  found  by  Dawson  in  hollow-tree  trunks  that  stood  in 
the  fresh-water  swamps  of  Nova  Scotia  during  the  time  our  continent  was 
green  with  the  ferns  and  clulnnosses  of  the  Coal  period.  With  these  bones 
are  mingled  the  shells  of  land-snails,  the  earliest  of  their  class  yet  found. 

In  deposits  of  cannel  coal  formed  in  fresh-water  ponds  in  the  great 
coal  swami)S  of  Ohio,  Newbt^iy  discovered  a  large  numl)er  of  species  of 
fishes  and  amphibians,  in  a  beautiful  state  of  preservation. 


llli 


LAKES   OF   NOHTH    AMKHICA. 


Kiutlu'i'  l)iick  still  in  the  records  of  the  past  are  other  frafrments  of  tlie 
earth's  history  sealed  uj)  and  pn-seivcd  in  lake  deposits.  The  heavy  h(^ds 
of  sandstone  coniposinj^  the  ("atskill  nioimtains.  and  forniinjr  h  part  of  the 
Devonian  system,  contain  shells  which  rescnihle  the  coverinj^-  of  fi'esh- 
water  moUnsks,  and  may  indicate  that  tla;  sands  in  which  they  were 
huried  are  of  huMu.tral  orij^in.  Here  the  evidenctf  of  terrestrial  lakes 
seems  to  end.  What  inland  water  hodics  existed  in  remote  Silurian, 
Camhrian,  and  Algonkian  times,  remains  to  be  discovered. 


its  of  tlic 
'iivy  ImmIs 
lit  of  the 
of  frt'sli- 
icy  were 
•ial  lakes 
Silurian, 


liAKIt  iir  NkUIII    A.MIJIKA. 


PLATK  22 


A   CHARACTERISTIC    SPECIMEN    OF    THINOLITE. 


SUPPLEMENT. 


TiiK  advance  mado  in  the  study  and  in  the  interpretation  of  the  meaning 
of  topograpliio  forms,  has  been  so  great,  es])ecially  in  America,  during  the 
present  (h'cuile,  that  I  am  sure  tlie  n'ader  will  he  int<'restfil  in  the  writings  of 
those  wlio  liav(i  made  this  important  departure  Irom  old  im  diods.  The  recog- 
nition that  hikes  are  transient  features  of  the  ever-cdiangiug  earth's  surface  ami 
come  and  go  during  cycles  of  topographic  development,  was  first  clearly  set 
forth  in  a  brief  j)aper  by  W.  M.  Davis, ^  which  is  here  rei)roduced. 


TitK  Classification  of  Lakks. 

Several  years  ago  I  \)resented  to  the  lioston  Society  of  Natural  History  a 
paper  on  the  classification  of  lake-basins,  in  which  the  many  varieties  of  lakes 
were  groujjcd  under  three  heads,  according  as  they  were  math'  by  constructive, 
destructive,  or  obstructive  processes.  The  first  heading  included  lakes  made 
by  mountain-folding  and  other  displacements ;  the  seccjnd  consisted  chiefly  of 
basins  of  glacial  erosion;  the  third  contained  the  greatest  number  of  varieties, 
such  as  lakes  held  by  lava,  ice,  and  drift  barriers,  ilelta  and  ox-bow  lakes,  and 
some  others.  The  elassitication  proved  satisl'iu;tory,  in  so  far  as  it  suggested 
a  systematic  arrangement  of  all  kinds  of  lakes  that  have  been  described ;  but 
it  now  appears  unsatisfactory,  inasmuch  as  its  arrangement  is  artificial,  with- 
out reference  to  the  natural  relations  of  lakes  to  the  develojtnuMit  of  the  drain- 
age systems  of  which  they  are  a  part.  A  more  natural  elassiflcation  is  here 
presented  in  outline. 

When  a  new  land  rises  from  below  the  sea.  or  when  an  old  land  is  seized 
by  active  mountain-growth,  new  rivers  establish  themselves  ui)ou  the  surface 
in  accordance  with  the  sIojjcs  i)resented,  and  at  once  set  to  work  at  their  long 
task  of  carrying  away  all  of  the  mass  tliat  stands  above  sea-level.  At  first, 
before  the  water-ways  are  well  cut,  the  drainage  is  (commonly  imi)erfcct: 
lakes  stand  in  tlie  undrained  dejjressions.  Such  lakts  are  tiic  numifest  signs 
of  immaturity  in  the  life  of  their  drainage  .system.  AVe  see  examples  of  them 
on  new  land  in  southern  Florida ;  and  on  a  region  lately  and  actively  dis- 
turbed in  southern  Oregon,  among  the  blocks  of  faulted  country  described  by 
Russell.  But  as  time  passes,  the  streams  fill  up  the  basins  and  cut  down  the 
barriers,  and  the  lakes  disappear.     A  mature  river  of  uninterrupted  develop- 

1  Science,  vol.  10,  1887,  pp.  14-',  lU. 


118 


SUPPLEMKNT. 


IB:! 


ment  has  no  sueh  immature  featiiros  remaining.  The  life  of  most  rivers  is, 
liowever,  so  long,  that  few,  if  any,  complete  tiieir  original  tasks  undisturbed. 
Later  mi untain-growth  may  repeatedly  obstruet  their  flow;  lakes  appear 
again,  and  the  river  is  rejuvenated.  Lake  Lueerrie  is  tlius,  as  Heim  has  shown, 
a  sign  of  local  rejuvenation  in  the  generally  mature  Keuss.  Tiie  head  waters 
of  the  Missouri  have  lately  advanced  from  such  rejuvenation;  visitors  to  the 
National  Park  nay  see  that  the  Yellowstone  has  just  regained  its  former 
steady  flow  by  ciitting  down  a  gate  through  the  Uiountains  above  Livingston, 
and  so  draining  the  lake  that  not  long  ago  stood  for  a  time  in  Paradise  valley. 
The  absence  of  lakes  in  the  Alleghany  mountains,  that  vas  a  matter  of  sur- 
prise to  Lyell,  does  not  indicate  any  ]»eculiarity  in  the  growth  of  the  moun- 
tains, but  only  that  they  and  their  drainage  system  are  very  old. 

The  disappearance  of  original  and  mountain-made  lakes  is  therefore  a  sign 
of  advancing  development  in  a  river.  Conversely,  the  formation  of  small 
shallow  lakes  of  quite  another  character  marks  adolescence  and  middle  life. 
During  adolescence,  Avhen  the  head-water  streams  are  increasing  in  number 
and  size,  and  making  rapid  concpiest  of  land-waste,  the  lower  trunk-stream 
may  be  overloaded  with  silt,  and  V)uild  up  its  flood-plain  so  fast  that  its  smaller 
tributaries  cannot  keep  pace  with  it :  so  the  lakes  are  formed  on  either  side  of 
the  Red  Kiver  of  Louisiana,  arranged  like  leaves  on  a  stem;  the  lower  Danube 
seems  to  present  a  similar  case.  The  flood-plains  of  well-inatured  streams 
have  so  gentle  a  shipe  that  their  channels  meander  through  great  curves. 
When  a  meander  is  abandoned  for  a  cut-off,  it  remains  for  a  time  as  a  cres- 
certic  lake.  When  rivers  get  on  so  far  as  to  form  large  deltas,  lakes  often 
collect  in  the  areas  of  less  sedimentation  between  the  divaricating  channels. 
Deltas  that  are  built  on  land  where  the  descent  of  a  stream  is  suddenly 
lessened  and  its  enclosing  valley-slo])es  disai)pear,  do  not  often  hold  lakes  on 
their  own  surface  ;  for  their  slope  is,  altiiough  gentle,  rather  too  steep  for  that : 
but  they  cor.imonly  enough  form  a  lake  by  obstructing  the  stream  in  whose 
vall<>y  they  are  built.  Tulare  Lake  in  southern  California  has  been  explained 
by  Whitney  in  this  way. 

T'he  contest  for  drainage  area  that  goes  on  between  streams  heading  on  the 
opposite  slopes  of  a  divide  sometimes  produces  little  lakes.  The  victorious 
stream  forces  the  divide  to  migrate  slowly  away  from  its  steeper  slope,  and 
the  stream  that  is  thus  robbed  of  its  head  waters  may  have  its  diminished 
volume  clogged  l)v  the  fan-deltas  of  side-branches  farther  down  its  valley. 
Heim  has  exjdained  the  lakes  of  the  Engadiuv!  in  this  way.  The  Maira  has, 
like  an  Italian  brigand,  plundered  the  Inn  of  tw(j  or  more  of  its  upper  streams 
and  the  Inn  is  consecpiently  ])onded  back  at  San  Moritz  and  Silvaplana.  On 
the  other  hand,  the  victorious  stream  may  by  this  sort  of  concpiest  so  greatly 
eidarge  its  volume,  and  thereby  so  (piickly  cut  down  its  tijtper  valley,  that  its 
lower  (,'ourse  will  be  flooded  with  gravel  and  sand,  and  its  weaker  side-streams 


SUrPLEMENT. 


m 


t  rivers  is, 
luUsturbed. 
Ices  appear 
has  shown, 
load  waters 
itors  to  the 

its  t'onner 
Livingston, 
[Use  valley, 
tter  of  sur- 

the  mouM- 

'fore  a  sign 

in  of  small 

middle  life, 

in  number 

unk-stream 

its  smaller 

ther  side  of 

ver  Danube 

■ed  streams 

eat  curves. 

e  as  a  cres- 

lakes  often 

channels. 

suddenly 

d lakes  on 

p  for  that : 

1  in  whose 

xplained 

ling  on  the 
victorious 

[slope,  an<l 

liininished 

ts  valley. 

Maira  has, 

■r  streams 

lana.     On 

|so  greatly 

|v,  that  its 

•-streams 


ponded  back.  No  cases  of  tliis  kind  are  described,  to  my  knowledgr.  tmt  they 
will  very  likely  be  found ;  oi  at  least  we  may  expect  them  to  ai)i)ear  when  the 
northern  branches  of  the  Indus  cut  their  way  backwards  through  the  inner- 
most range  of  the  Himalaya,  and  gain  jiossession  of  the  drainage  of  the 
plateaus  beyond ;  for  then,  as  the  liigh-level  waters  iind  a  steep  outlet  to  a 
low-level  discharge,  they  will  carve  (mt  canons  the  like  of  ivliich  even  Dutton 
has  not  seen,  and  the  heavy  wash  of  waste  will  shut  in  lakes  in  lateral  ravines 
at  many  points  along  the  lower  valleys. 

In  its  old  ;;ge,  a  river  settles  down  to  a  quiet,  easy,  steady-going  existence. 
It  has  overcome  the  difficulties  of  its  youth,  it  has  corrected  the  defects  that 
arose  from  a  period  of  too  rapid  growth,  it  has  adjusted  the  contentions  along 
tlie  boundary-lines  of  its  several  members,  and  has  established  peaceful  rela- 
tions with  its  neighbors  :  its  lakes  disappear,  and  it  flows  along  channels  that 
meet  no  ascending  slope  on  their  way  to  the  sea. 

Certain  accidents  to  whicb.  rivers  are  subject  are  res]ionsil)le  for  many 
lakes.  Accidents  of  the  hot  kind,  as  they  may  be  called  for  elementary  dis- 
tinction, are  seen  in  lava-flows,  which  build  great  dams  across  valleys :  the 
marshes  around  the  edge  of  the  Snake  river  lava-sheets  seem  to  be  lakes  of 
this  sort,  verging  on  extinction  :  crater  lakes  are  associated  with  other  forms 
of  eruption.  Accidents  of  the  cold  kind  are  the  glacial  invasions:  we  are 
perhaps  disposed  to  overrate  the  general  importaTice  of  these  in  the  long  his- 
tory of  the  world,  because  t''e  last  one  was  so  recent,  and  has  left  its  numerous 
traces  so  near  tin'  .^enters  ol  our  civilization  ;  but  the  tem})orary  importance  of 
the  last  glacial  ac;5ident  in  explaining  our  home  geography  and  our  luiman 
history  can  hai'dly  be  exaggerated.  During  the  ])resence  of  the  ice,  especially 
during  its  retreat,  short-lived  lakes  were  common  about  its  margin.  We  owe 
many  prairies  to  such  lakes.  The  rivers  running  fnun  the  ict-front,  overloaded 
with  sand  and  silt,  hlled  up  tlieir  valleys  and  pcmded  back  their  non-glacial 
side-streams  ;  tlieir  shore-lines  have  been  briefly  described  in  Ohio  and  Wis- 
consin, Imt  the  lakes  themselves  were  drained  when  tlu-iv  flood-plain  barriers 
were  terraced  ;  they  form  an  extinct  species,  closely  allied  to  the  existing 
Danube  and  Red  liiver  type.  As  the  ice-sheet  melts  away,  it  discloses  a  sur- 
face on  which  the  drift  has  been  so  irregidarly  accumulated  that  the  new 
drainage  is  everywhere  embarras.^ed,  ar.d  lakes  are  for  a  time  very  numerous. 
Moreover,  the  erosion  accomplished  by  the  ice,  especially  near  the  centers  of 
glaciation,  must  be  held  responsible  for  many,  though  by  no  means  for  most, 
of  these  lakes.  Canada  is  the  American  type,  and  Finland  the  European,  of 
land-surface  in  this  condition.  The  drainage  is  seen  to  be;  very  immature,  but 
the  immaturity  is  not  at  all  of  the  kind  that  characterized  the  first  settlement 
of  rivers  on  these  old  lands  :  it  is  a  case,  not  of  rejuvenation,  but  of  regenera- 
tion ;  the  icy  baptism  of  th.;  lands  has  converted  t\oir  ,-ti  ,ns  to  a  new  spirit 
of  lacustrine   hesitation  unknown  before.     We  cannot,   liowever,  expect  the 


1-20 


SUPPLEMENT. 


conversion  to  last  very  lon^  :  there  is  already  api)aront  a  iKU-kslidiuj,'  to  the 
earlifM-  faith  of  steady  flow,  to  which  undisturbed  rivers  tulliere  closely  through- 
out their  lives. 

Water-surface  is,  for  the  needs  of  man,  so  unlike  lund-surface,  that  it  is 
natural  enough  to  include  all  water-basins  under  the  single  geographic^  term, 
'  lakes.'  Wherever  they  ocfMir,  —  in  narrow  mountain-valleys  or  on  broad,  level 
plains;  on  divides  or  on  deltas;  in  solid  rock  or  in  alluvium,  —  they  are  all 
given  one  name.  Jiut  if  we  in  imagination  lengthen  our  life  so  that  we  wit- 
ness the  growth  of  a  river-system  as  we  now  watch  the  growth  of  plants,  we 
must  then  as  readily  perceive  and  as  little  confuse  the  several  physio-^raidiic 
kinds  of  lakes  as  we  n'>w  distinguish  the  cotyledons,  the  leaves,  thv.  galls,  and 
tilt'  tlowv-.'s,  of  a  quickly  growing  annual  that  produces  all  these  forms  in 
appropriate  order  and  position  in  the  brief  course  of  a  single  summer. 


W.   M.    DAVIS. 


CAMiiKiixiK,  Mass.,  Septemler  7,  1887. 


Lakes  of  North  Amkrica 


Plate  2;<. 


•  .ii* 


SKETCH    OF   PM^AiMIL    lounn 


u,    HrHAMlu    LAKE.    NEVADA. 


\ 


II^DEX. 


Abbott,  Humphreys  and,  Cited  on  rafts  in 

Ked  river,  La.,  27. 
Abert  lake,  Oregon,  Analy.si.s  of,  72. 

( )rij?in  of,  ;i(). 

Aga.ssiz,  Lake,  Description  of,  103-106. 

Reference  to,  J. 

Aleutian  islands,  Lakes  on,  26. 

Alf;ae,  I'recipitation   of  lune  and  iron  by, 

76,  77. 
Alluvial  cones,  Obstruction  of  drainage  by,  6. 
Analysis  of  the  waters  of  alkaline  and  saline 

lakes.  Table  of,  72. 
Analysis  of  the  waters  of  fresh  lakes,  65-  57. 

Great  Salt  lake,  by  E.  Waller,  81. 

Mono  lake,  by  T.  M.  Chatard,  ss. 

St.   Lawrence  river,  by  T.  S.  Hunt,  60. 

Andrews,  E.,  Cited  (,n  erosion,  60. 
Annie,  Lake,  Cal.,  Origin  of,  10. 
Aqueous  agencies.  Lake  biisins  due  to,  5-10. 
Areas  of  Laurentian  lakes,  58. 
Atmospheric  agencies,  basins  due  to,  3-5. 
Au  Train  island.  Gravel  spit  on,  48. 

Bars,  Origin  of,  47,  48. 

Bear-wallows,  28. 

Beaver  dams.  Lakes  formed  by,  27. 

Belleville,   Out.,    Height  of    ancient    beach 

at,  100. 
Bischof,  G.,  Cited  on  chemistry  of  water,  56. 
Bolsena,  Lago  di,  Ital.,  Mention  of,  20. 
Bonney,  T.  G.,  Cited  on  rook-basins,  41. 
Bonneville,  I^ake,  Delt  is  in,  60. 

Description  of,  106-109. 

Lakes  in  basin  of,  20. 

Overflow  of,  .30. 

Borgne,  Lake,  La.,  Origin  of,  8. 
Bracciano,  Lago  'li,  IlaL,  Mention  of,  20. 
Brienz,  Lake,  Switz..,  Hefer .nee  to,  7. 
Brighani,    A.    P.,   Cited    oi;    Finger    lakes, 

N.  Y.,  16. 
Buffalo.  N.  v..  Rise  of  water  at,  39. 
Buffalo-wallows,  28. 


Calderas  or  crater-rings,  20. 

Canadian  river,  N.  M.,  Lava  flow  In  cation 

of,  18. 
Carboniferous  lakes.  Brief  notice  of,  116. 
Cascades,  Basins  excavated  by,  5-<5. 
Caspian  sea,  Brief  account  of,  (iO. 
Ca.stani,  Lake,  Alaska,  Origin  of,  11. 
Catsk'll  Mts.,  Reference  to,  116. 
Cayuga,  Lake,  X.  Y.,  Origin  of,  16. 
Chaix  hills,  Alaska,  Lakes  near,  11,  12. 
Chaniplain,  Lake,  Terraced  borders  of,  02. 
Chatard,  'J\   M.,  Analysis  of  the  water  of 

Mono  lake  by,  88. 

Cited  on  aiuilysis  of  lake  water,  72. 

Chelan  City,  \Va.sh.,  Mention  of,  '">♦!. 
Chelan,  Lake,  Wash.,  Description  of,  65-(i9. 
Chemical  action,  Basins  due  to,  31,  32. 
Chemistry    of    lake    waters,    56-60,    60-77, 

81-88. 
Chicago,  111.,  Rise  of  water  at,  34. 
Cinder  Cone,  Cal.,  Lakes  near,  18. 
Cleveland,  ().,  Erosion  near,  61. 
Climati',  Influence  of,  on  lakes,  37,  38. 
Climatic  conditions.  Relation  of,  to  lakes,  64. 
Coast  Survey,  U.  S. ,  Chavts  of,  9. 
Cochituate,  L.ake,  Mass.,  Origin  of,  17. 
Color,  Trevailing,  of  lake  beds,  41. 
Columbia  river,  Wash.,  Lakes  in  old  channel 

of,  6,  6. 
Commerce  of  tlie  Laurentian  lakes,  61,  62. 
Como,  Lake,  Ital.,  Meniiim  of,  15,  64. 
Com.stock,  v\  B.,  Cited  on  Lake  Survey,  67. 
Coon  butle,  Ariz.,  Description  of,  21,  2'?.. 
Crater  lake.  Ore.,  Description  of,  20,  21. 

Mention  of,  64. 

Crator  lakes,  Origin  of,  10. 
Crosman,  C,  Records  of  erosion,  by,  60. 
Crolon  river,  N.  Y.,  Soluble  matter  in,  56. 
Currents,  Wavei  and,  in  lakes,  33,  34. 

Dana,  E.  S.,  Cited  on  thiiiolitic  tufa,  112. 
Dana,  Mt.,  Cal.,  View  from,  K4,  85. 


122 


INDEX. 


pi 

m 


Davis,  W.  M.,  Cited  on  classification  of 
lalvcs,  1,  117-120. 

Cited  on  crater  lakes,  19.       • 

Cited  on  lakes  of  Ked  river,  8. 

Cited  on  lakes  retained  by  deltas,  7. 

Dawson,  .J.  W.,  Cited  on  carboniferous  fos- 
sils, 115. 

-  — Cited  on  Pleistocene  history  of  Lauren- 
tian  basin,  102. 

Dawson,  \V.  M..  Cited  on  Lake  Yukon,  17. 

Delta  in  Lake  St.  Clair,  Origin  of,  -10. 

Deltas,  Formation  and  structure  of,  48-01. 

Deltas,  Lakes  on,  8. 

Dendritic  tufa,  Origin  of,  110. 

Detroit  river.  Area,  water-shed,  etc.,  of,  68. 

Diastropliisni,  Lakes  due  to,  28-:Jl. 

Diatoniaceous  earth,  Origin  )f,  42. 

Dieulafait,  M.,  Cited  on  precipitation  of 
salts,  74. 

Diller,  J.  S.,  Cited  on  lakes  in  Cat.,  18. 

Dirt  glacier,  Ala.ska,  Lake  retained  by,  11. 

Druniiiiond  Inke,  Va.,  Origin  of,  26. 

Dunes  retaining  lakes,  4. 

■atton,  C.  E.,  Cited  on  Crater  lake.  Ore.,  20. 

Sarttiquakes,  Bai^ms  due  to,  25,  26. 
En'^.  Lake,  Currents  i      M. 

Bfccts  of  CJtl*'   'ii    ;4. 

Biwsitm  of  the  shores  of,  61. 

Ifmlmnkineiits,  ( >rigin  of,  46-48. 
■■■HI  of  laks  shores.  60. 

fltaiik-ba^DS,  Description  of,  20,  30. 

Heference  to,  2. 

Finger  laktw,  N.  Y.,  Origin  of,  16. 
Fisheries  of  the  Laurentian  lakes,  62. 
>1orida.  Lakis  on  new  land  in,  1. 
Flow  of  streams,  Influence  of  lakes  on,  88,  39. 
Fort  Bidwell,  Cal.,  Lake  Annie,  near,  10. 
Fossils  in  sediments  of  lakes  Bonneville  and 
Lahontan,  114. 

Gaylussite,    formation    of,   in    Soda   lakes, 

Nev.,  73,  74. 
G«neva,  Lake,  Switz.,  Delta  in,  91. 

Purity  of  water  in,  40. 

Gilbert,  G.  K.,  Citel  cm  age  of  Great  Salt 

lake,  82. 

Cited  on  Cn.,n  hntfH.  Ariz..  21,  22,  24. 

Cited  on  ice-walls.  .v>.  53. 

Cited  on  Lake  Bonneville,  106. 


Gilbert,  G.  K.,  Cited  on  lake  in  Ice  Spring 
butte,  Utah,  19. 

Cited  on  lunar  craters,  24,  25. 

Cited  on  Pleistocene  history  of  Lauren- 
tian basin,  9(1. 

Cited  on  wind-erosion  basins,  3. 

Glacial  agencies,  Lakes  due  to,  10-17. 

Cilaciers,  Lakes  on,  10,  11. 

(Jlen  Hoy,  Scotland,  Ancient  beaches  in,  12. 

Grand  Coulee,  Wash.,  Lakes  in,  5. 

Great  Basin,  Origin  of  lakes  in,  2. 

Pleistocene  lakes  of,  106-114. 

Great  lakes,  Plei.stocene  history  of,  00-103. 

(Jreat  Plain  of  the  Columbia,  lakes  on,  4,  5-6. 

Great  Salt  lake,  Utah,  Analysis  of,  72. 

Description  of,  77-83. 

Precipitation  of  sodium  sulphate  in,  75. 

See  also  Laurentian  lakes. 

Gustavila,  Lake,  Mex.,  Mention  of,  20. 

Gypsum,  Bjisins  due  to  solution  of,  32. 

Hamilton,  Ont.,  Height  of  ancient  beach 
at,  100. 

Ilayden,  F.  V.,  Cited  on  Twin  lakes,  Col.,  14. 

Hayes,  C.  VV.,  Cited  on  lakes  in  \la.ska,  17. 

Hudson  river,  N.  Y.,  Soluble  matter  in,  56. 

Hull,  E.,  Cited  on  Laacher  See,  10. 

Ilumlioldt  lake,  Nev.,  Analysis  of,  72. 

Origin  of,  10. 

Humphreys  and  Abbott,  Cited  on  rafts  in 
Red  river.  La.,  27. 

Hunt,  T.  S.,  Analysis  of  water  of  Si.  Law- 
rence by,  60. 

Huron,  I>ake,  Area,  depth,  eic,  of,  58,  50. 

Currents  in,  -34. 

Ice-lniilt  walls,  Origin  of,  51-53. 
Ice  Spring  butte,  Utah,  Lake  in,  10. 
Inland  Salt  Co.,  Utah,  Operations  of,  82. 
Iroquois,  Lake,  Brief  account  of,  99. 

Judd,  J.  W.,  Cited  on  Caldenis,  20. 

King,  C,  Cited  on  Lake  Lalumtan,  106. 

Cited  on  thinolite,  110. 

Klamath  lake,  (hv.,  Mention  of,  20. 
Krakatoa,  Eruption  of,  21. 

LaaohtT  Set ,  Germany.  Mention  of   19. 
Ijiiontan,  Lake,  Nev.,  Description  of,  106- 
114. 


e  Spring 


;  Lauren- 

;i. 

17. 

les  in,  12. 


96-103. 
)n,  4,  6-6. 

E,  72. 

ate  in,  76. 

■;  20. 
,  32. 

ent  beach 

8,  Col.,  14. 
\laska,  17. 

lev  in,  56. 
I. 
2. 

rafts  in 

!^.     Law- 

08,  50. 


^f,  82. 


106. 


INDEX. 


128 


IP. 

of,  106- 


Lahontan,  Lakes  in  basin  of,  10,  20. 
Lake  Survey,  U.  S.,  Cliarts  of,  0,  48,  40. 

Tides  observed  by,  33. 

Work  of,  57,  58. 

Land  slide.s,  Basin  formed  by,  31. 
Laurentian  basin,  I'leistocene  history  of,  00- 

103. 
Laurentian  lakes.  Account  of,  57- 

Areas  of,  58. 

("olor  of  clays  in,  41. 

Currents  in,  33,  34. 

Krosion  of  the  shores  of,  00. 

See  also  Great  lakes. 

Lawson,  A.  C,  Cited  on  I'leistocene  history 

of  Laurentian  basin,  96,  KKt. 
Le  Conte,  .John,  Cited  on  Lake  Tahoe,  64. 
Ob-servations  by,  in  Lake  Tahoe,  Cal. — 

Nev.,  35-.']7. 
Life  histories  of  lakes,  90-95. 
Lithoid  tufa.  Origin  of,  110. 
Lockyer,  N.,  Cited  on  meteoric  bypotiaesis, 

24. 
Loe.ss,  Origin  01.  11. 
Logan,  Utah,  Delta  near.  iO. 
Loniis  lake,  India,  l^scnijution  of,  2H. 
Lyell,  C.  Cited  00  raft*  in  lied  river.  La.,  27. 

Maggiore,  Lake,  Ital.,  Mention  of,  64. 

Reference  to,  15. 

Malaspina  glacier,  Lakes  near,  ft,  lil. 

Manitoba,  L.akes  in,  7. 

Manitou  island,  Lake  Michigan,  Sea  cliff  on, 
42. 

Miirjelen  lake,  Switz. .  ( )rigin  of,  1 1 . 

Mechanical  .sediments,  Deposition  of,  41. 

McGee,  W.  .!.,  Cited  on  New  Madrid  earth- 
quake, 25. 

Meteoric  hypothesis.  Reference  to,  24. 

Meteors,  Basins  due  to  impact  of,  24,  23. 

Michigan,  Lake,  Area,  depth,  etc.,  of,  58,  59. 

Currents  in,  34. 

■ Kffects  of  gale  on,  34. 

KroH'on  of  the  shores  of,  60,  61. 

Influence  of,  on  climate,  38. 

Mississippi  delta,  "Mud  lumps"  on,  28. 

Mississippi  river.  Soluble  matter  in,  56. 

Mono  lake,  t^al.,  Analysis  of,  72,  88. 

Crater- lake  in.  19. 

Description  of,  83-89. 

Lake  on  island  in,  24. 

Moraine  lakes  near,  14. 


Mono  Lake,  Cal.,   Recent  fault  near,  30. 

Tufa  bowl  near,  32. 

Moon,  Origin  of  craters  on,  24. 
Mora  river,  X.  M.,  Lava  flow  in  cafionof,  18. 
Moses  lake.  Wash.,  Origin  of,  4. 
Mountain  lakes.  Examples  of,  63-09. 
Muir,  J.,  Cited  on  lake   in   Stikine  valley, 
Alaska,  11. 

New  land  areas,  lakes  on,  1-3. 

New  Madrid  earthquake,  Lakes  formed  by, 

25. 
Niagara  river,  Area,  water-shed,  etc.,  of,  58. 
Newberry,   .1.    S.,    Cited  on    lakes  in    coal 

swamp.s,  115. 

Oldlinm.  K.  I).,  Cited  on  Lon.is  lake,  Ind.,  23. 

Ontario.  I^ke,  Area,  depth,  etc.,  of,  58,  59. 

-     -  Currents  in.  34. 

Oiilitic  suiiiid.  Origin  of,  77. 

Organic  agencies,  BHsins  due  to,  26-28. 

Ow»-iiK  lake,  Cal.,  Analysis  of,  72. 

Ox-tJijw  lakes.  <  »righi  1  '1,  8. 

Parks  of  ('oif»rado.  Origin  of,  15. 
Peat  bogs,  Dramttige  of,  42. 
Pepin,  Lake,  Origin  of,  7. 
Perkins,  K.  A.,  Cited  on  Seiches,  35. 
Play  a  lakes.  Origin  of.  70,  71. 
Pleistocem  iake-beds.  Coh)r  of,  41. 
Poe,  O.  M.    L<\M*-  mtrw-ys  by,  58. 
Pontchartraui.  Lake,  La.,  Origin  of,  8. 
Powell,  J.  \^'  .  Cited  00  (^structions  in  Colo- 
rado river.  7 
Precipitates  troni  saline  iaiites,  71-77. 
Pyramid  lake,  Nev.,  Analynas  of,  72. 

Rain-fall  -a  Lauivntian  basin.  '>9. 
RajEtown,  Xev.,  Salts  formed  in  lakes  near, 
73. 

See  a,\m>  Soda  lakes. 

Samsay,  A.  C,  Cited  on  rock-basins,  15. 
Bed  river.  La.,  Lakes  on,  8. 

Timber  rafts  in,  27. 

Rhone,  Delta  of ,  91. 

Kock-basins  maile  by  glaciers,  13,  14. 

Rock-basins,  Origin  of,  4. 

Roth,  J.,  Cited  on  chemistry  of  water,  55. 

Rothplitz,  A.,  Cited  on  oolitic  sand,  77. 

Rush,  Lake,  Utah,  <  >rigin  of.  9,  10. 

Russell,  Tnomas,  Cited  on  evaporation,  59. 


124 


INDEX. 


St.  Clair,  Lake,  Area,  water-shed,  etc.,  of, 

68. 

Delta  formed  in,  40. 

St.  Clair  river,  Area,  water-shed,  etc.,  of, 

58. 
St.  Lawrence  basin.  Rain  fall  in,  59. 
St.  Lawrence  river,  Analysis  of,  CO. 

Volume  of,  58. 

St.  Mary's  river.  Area,  water-shed,  etc.,  of, 

68. 
St.  Mary's  river.  Rise  of  water  in,  .34,  39. 
Saline  lakes,  De.'<cription  of,  (59-80. 
Sault  de  St.  Marie,  see  also  Saint  Mary's 

river. 

Vessels  passing,  (51. 

Sandusky,  O.,  Lakelets  near,  28. 
Sea  cliffs.  Origin  of,  43-45. 
Sediments  in  lakes,  .39,  40. 
Seneca  lake,  N.  Y. ,  Deltas  in,  49,  50. 
Seiches,  Brief  account  of,  .35. 
Sevier  lake,  Utah,  Analysis  of,  72. 
Sink-holes,  Ponds  formed  in,  31. 
Smoke  cieek  desert,  Nev.,  Lakes  on,  27,  28. 
Schermerhorn,  L.  Y.,  Cited  on  physical  feat- 
ares  of  Liliirentian  lakes,  68. 
Soda  lake,  Xev.,  Analysis  of,  72. 

Origin  of,  19. 

See  also  Ragtown  ponds. 

Soap  lake,  Wash.,  Analysi.s  of,  72. 
Spencer,  ,i.  W.,  Cited  on  I'leistocene  history 

of  Laurentian  baain,  9(5,  102. 
Stevenson,  J.  .1. ,  Cited  on  lava  flow  in  Ifew 

Mexico,  18. 

Cited  on  Twin  lakes,  Col.,  14. 

Stikine  river.  Alaska,  Olacial  lake  in  valley 

of,  11. 
Stockton,  Utah,  Small  lake  near,  9,  10. 
Stockton  bar,  Utah,  Brief  account  of,  10. 

Map  of,  12. 

Suez  Canal,  Commerce  of,  61, 

Superior,  Lake,  Ancient  beaches  on  shores 

of,  101. 

Area  of,  57. 

——Area,  depth,  etc.,  of,  58,  59. 
— i — Color  of  clays  in,  41. 

Currents  in,  34.  . 

Precipitous  shores  of,  45. 

Rise  of  water  in,  .39. 

Sand  bars  on  shore  of,  48. 

Swallow-holes,  PimuIs  formed  in,  31. 
Sweden,  Lake  ores  of,  77. 


Synions,  T.  W.,  Cited  on  the  Upper  Colum- 
bia, 08. 
Syracuse,  N.  Y.,  Scalts  from  brines  of,  73. 

Tahoe,  Lake,  Cal.— Nev.,  Depth  of,  21. 

Description  of,  03-(55. 

Mention  of,  07,  08. 

Temperature  of,  35-37. 

Tarr,  R.  S.,  Cited  on  Lake  Cayuga,  10. 

Taylor,  F.  B.,  Cited  on  delta  in  St.  Clair 
lake,   40. 

Cited  on  Pleistocene  history  of  Lauren- 
tian basin,  9(5-101. 

Temperature  of  deep  lakes,  36,  36. 

Lake  Tahoe,  04. 

Terraces,  Origin  of,  44-46. 

Tertiary  lakes,  Brief  notice  of,  115. 

Thinolite,  Nature  of,  110. 

Thinolitic  tufa.  Origin  of,  110-113. 

Thun,  Lake,  Switz.,  Reference  to,  7. 

Tides  in  Laurentian  lakta,  33. 

Toledo,  0.,  Rise  of  water  at,  34. 

Toronto, .Can.,  Height  of  ancient  beach  at, 
100. 

Topography  of  lake  shores,  43-49. 

Toiilca,  Mt.,  Mex.,  Lake  in,  19. 

Toyatte  glacier,  Alaska,  Lake  retained  by, 
li. 

Truckee  river,  Obstructed  by  sand,  4. 

Tiiftt  in  Lahniitiin  Imsin,  110-114. 

Tulare,  Lake,  Cal.,  Origin  of,  fl. 

Tundras,  Origin  of  lakes  on,  26. 

/'win  lakes.  Col.,  Origin  of,  14. 

Tyrroll,  J.  B.,  Cited  on  ice-walls,  52. 

U.  S.  Fish  Commission,  Cited  on  fisheries  of 

Laurentian  lakes,  0. 
Upham,  Warren,  Cited  on  Lake  Agasslz,  7, 

104 
Cited  on  lakes  Walden  and  Cochituate, 

17. 

Victoria  Nyanza,  Lake,  Area  of,  67. 
Volcanic  agencies.  Lakes  due  to,  17-24. 
Volcanic  dust.  Obstruction  of  drainage  by,  4. 

Wakatipu,  Lake,  N.  Z.,  (M^n  of,  15. 
Walden,  Lake,  Miiss.,  Origin  of,  17. 
Walker  lake,  Nev.,  Analysis  of,  72. 
Waller,  E.,  Analysis  of  water  of  Great  Salt 
lake  by,  81. 


INDEX. 


Jpper  Colum- 
ncs  of,  73. 
1  of,  21. 


iga,  16. 

in  St.  Clair 

'  of  Lauren- 

10. 


Warren,  G.  K.,  Cited  on  Lake  Pepin,  7. 

Cited  on  outlet  of  Lake  Agassiz,  104. 

Warren,  River,  Source  of,  104. 
Watkins,  N.  Y.,  Deltas  near,  40,  60 
Watertown,  N.  Y.,  Height  of  ancient  beach 
at,  100. 

Waves  and  currents  of  lakes,  33-39 
Weather  Bureau,  U.  S.,  Currents  in  Lauren- 

tian  lakes  observed  by,  33,  34 
Weed,   W.    IL,   Cited  on    deposits  of   hot 

springs,  77. 
White,  A.  C,  Cited  on  ice- walls,  52. 


125 


Wind-erosion  basins,  f  )rigin  of  3 

Winchell,  A.,  Cited   on    iHotherinal.s  of  the 

Lake  Ilegion,  38. 
Winnenmcca  lake,  Nev.,    Analysis  of,  72. 
Winnipegasie,  Lake,  Ice-walls  of,  52. 

Yellowstone  park.  Precipitates  from  watera 
m,  70,  77. 

Yukon,  Lake,  Ahiska,  Origin  of.  17   13 
Yukon  river,  Alaska,  Drift  timber  in,  27. 

Zuyd^r  Zee,  Crigin  of,  8. 


3. 

>,  7. 


t  beach  at, 

Dtained  by, 
1,4. 


52. 

fisheries  of 
Agassiz,  7, 
}ochituate, 


7-24. 
lage  by,  4. 


15. 


jreat  Salt 


_aVimenta/ 

r^  nomm:  bldg.  ^^^ 


^     JM  2  4 


?<r 


^/f^ 


iifoarcei  mi  ^«^^ 


.if>^ 


.<^^ 


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